Why Do People HATE Cat ACERT Engines? 

Josh, you need to be teaching somewhere. You are easy to understand and you have great communication skills

Normal engineering thoughts: nothing was ever made to eat it’s own shit🤷🏼‍♂️ EGR- Watch this 😏

I went to school for this and have been working in the industry for a few years and this was the best explanation of emissions systems I've seen.

Never saw this guy in my life. His video just came on and couldn’t stop watching him. You have to love people that know their shit and are able to explain the theory behind it. Nice!

I have a C15 Acert (NXS24662) It has been really good to me 1,4700,000. Going for it first inflame in a few weeks.

I'll keep my old 3406b all mechanical. Never any problems, reliable, good fuel economy and pushing around 650 hp. And very easy to work on were I can do most of my own work.

Most guys nowadays rebuild them with 16:1 compression and delete the ivas. Keep the twins, good tune and you can have a good reliable engine with 700hp. As always thank you Josh for a very informative video! 👍👍

I drove a 2011 Peterbilt with a C13. What a nightmare regarding the Acert contraption. Every 6 months it was guaranteed to go in for replacement. My boss, finally pissed enough money away because of it decided to delete it along with the DPF. The truck went from barely being able to drive 60 Mph fully loaded and having to fuel up every 2 days to after the delete, to being able to hit 80 mph fully loaded & being able to fuel up every 3 days. What a difference. I drove that truck 1.2 million miles & it was a good truck once it was deleted.

I’m a diehard CAT engine fan. I drove an 03 kenworth with a 550hp c-15 single turbo. Boy she’d scoot. Then I went to a 06 Detroit 14.7. It was alright. Then the biggest POS a maxxforce. I mean total junk. 2 egr coolers under warranty, a high pressure fuel pump under warranty and 4 egr valves under warranty. We live in the rust belt in Michigan and we were constantly changing coolant and oil pipes. Constant corrosion issues with lights. ABS lights on wet roads, way overly complicated hvac systems to keep us warm that we’re also constantly giving fits. Then four years ago I bought a Fitzgerald glider. Oh man talk about reducing maintenance cost! It’s got a 12.7 Detroit with 540k on it now. The only thing I had troubles with was the cylinder head leaking oil which was done twice because the front structure also was part of the problem. She’s the best truck I’ve owned so far and definitely believe I’ll get a million plus before the next overhaul. Still partial to CATS tho. Keep the vids coming. 👍

Thanks that was a lot information and I m glad I m out of the trucking business. If I ever had another truck it would be pre emissions and elogs. I’m so tired of government interference.

I drive a 2004 school bus with the C 7 210 hp engine, it’s a good enough for me in the school bus but a few years ago a drove a 3406 475 hp in a KW hauling fuel and it’s a big difference in the power . Keep up the good job of letting us know about cat engines .

Good explanation , l have 06 cat c15 and your right about injector harness . I just replaced both a couple of weeks ago broken wire . They had over 700,000 miles on them , engine light came on . I've had this truck for 11 years , had a platinum kit done 7 years ago . Its been pretty good to me , good power half decent fuel mileage . What l like most is the independent Cat dealer network , when l have engine issues l dont take it to a peterbilt dealer l take to a Cat shop . Everyone of those Cat shops over the last 25 years have been really good , they have a lot of knowledge and experience . They always fix the problem and get me on my way in a timely fashion . I have had other trucks in that 25 year period all had Cat engines in them . Only reason I have had this truck so long is it has a Caterpillar , and when it comes time for in frame l will not hesitate .

The worst part for everyone with early IVAs was [I believe if memory serves] 'IVA #x not responding' were troubleshot by Cat by swapping IVA heads, putting it all back together, have the customer run it until a code returned, then see if the code followed the head or stuck on one cylinder. As a service manager at that time, I fought Cat tooth and nail because they refused to pay for two repairs with only one failure. After a while, iva heads just got replaced, -7 codes got new sokenoids, then those damned ARD heads came out. Constantly updating head designs, pissing off customers because Cat would not cover spark plugs even on a failed warranty ARD head. Ugh. I don't miss those days. That said, I was an International service manager during the Maxxforce days, so times got way, way worse.

I run water injection on my 6nz c-15, which significantly reduces heat in the combustion chambers. This is a very good way to reduce or eliminate Nox. It also increases the torque of the engine by about 25 to 30%. I see a significant reduction in coolant temperature and also EGTs. I wouldn't run without it Too many advantages with no downside other than the cost and having to fill the water tanks. It will NOT damage the engine AT ALL if properly installed and operated correctly. Sno-performance has an excellent system. If you install this system I highly recommend you install at least a 30 gallon tank. I have 2 such tanks. These large engines can burn 60 to 80 gallons a day. I have been running it for over 10 years now, and have never had any problems with it or damage to my engines. This is the second engine I have run it on. NOTE; it's only effective on hills, and steep grades. It does not even activate on flat land.

There is another way to solve this problem, politically, isolate the heavy truck engine line to its own LLC, make a very simple and reliable engine that doesn’t meet the EPA’s standards(what the customer wants), pay the fines, get government stimulus (your fine back) because the business isn’t viable do to the fines, and the line is an infrastructure necessity. To beat the government, beat them at their own game...

I have a cat c 15 2007 acert mxs with 1444567 millon miles with no overhaul yet still running strong the acert system until 2007 make a little bit more complicated but no body can’t beat that boost,mine run 10 000 miles in every 21 days nonstop pulling flatbeds loads it’s just a beast with 3.55 rears and 13 eaton god bless caterpillar 🐛

Love these CAT “lessons”. I’m so glad I have a 2004 C7. The potential HEUI issues scare me enough.

One reason C15 ACERTS weren’t liked that much in Australia was because the engines were designed to lug down at lower rpm than the single turbo C15s and 3406s. It just doesn’t work when you’re running weights of minimum 65 tons up to 200 tons with multiple trailers. Also if one turbo goes out, you’ve got to replace both as a rule. Any wiring under the valve covers has to be replaced fairly regularly because it cooks under our hot conditions. At least we didn’t have to run particulate filters and the rest of that crap on our ACERTs when they were installing them in our new trucks. Now if only they’d gone to using DEF like the other engine manufacturers they’d probably still be around...

ACERT - Advanced Cash Excruciating Removal Technique.

The whole NOX thing is what sticks in my craw. NOX goes up with leaner burns. Within limits of engine destruction safety, leaner burn results in less fuel burned. One of the ways to reduce NOX, along with the various after treatments, is to lower the AFR, resulting in poorer mpg. So the net result, all else being more or less equal, is more fuel burned to "reduce emissions". That seems like a paradox to me.

00:55 Part 1: What is Acert? 02:55 Part 2: Medium-duty engines 04:37 Part 3: Heavy-duty engines 07:28 Part 4: Particulate matter 08:47 Part 5: NOx 10:15 Part 6: IVA's and VVA's 12:34 Part 7: A turn for the worse 13:55 Part 8: Particulate matter, part 2 17:02 Part 9: NOx, part 2 17:55 Part 10: Is this EGR? No, this is CGI. 20:01 Part 11: Blow-by 22:21 Part 12: Fuel systems 23:14 Part 13: Conclusion

I love my ‘05 Acert! Had mine overhauled last November after 1.6 million and nothing more other than maintenance items and like Josh said, the occasional IVA problem which was an easy fix.

ACERT Advanced Combustion Emissions Research Technology. It worked in some engines. It was a very small injection of fuel before the injection cycle. The idea was to add fuel to fire (pre-ignition) at TDC +- (depending on flash file) and burn all of the fuel, instead of adding fuel to compression that caused ignition but did not burn all of the fuel before being expelled through the exhaust. Every injector fired twice which is the reason trim files were very important. Incorrect trim file would cause excessive fuel consumption. Great video!

Great video to understand all this engines complexity. I’m learning to deal with my Land Rover Discovery 2 with a Td5 engine now with 250,000 Km. Got rid of EGR system and having some blow-by. Initially thought it was not normal. Tried venting to atmosphere (draft hose-tube) but had to re-connect CCV hose to the depression valve in the inlet turbo hose. The problem was low turbo vaccum in depression valve at inlet turbo hose because it was cracked causing not enough vacuum to fully open the depression ccv valve to get rid of blow-by fumes. Better left all systems stock. Greetings from Guayaquil, Ecuador 🇪🇨

I work on c13 LEE Acerts everyday in MCI buses. The engine really is good. We have 18 of them and never had a major engine failure. I find if you change the ARD every year or so you're golden. I have a record of every ARD changed and for us and the type of miles our buses do, the ARD will fail between 10 and 14 months. Also we change the DPF around every 2 to 3 years. Do that and keep up with maintenance and you'll last forever. They all have about 900k of them. The only other issue iv been finding is high crank case pressure which pushes the oil out the stick. You NEED to not overfill them and you must change the crank case filter!! Also noticed the rear main housing behind the bell housing leaks alot. Gotta take it apart, changed the gasket and lock tight the bolts. Also gray silicon it too Injectors last forever, turbos, water pump, oil pump, IVA, EGR also last forever. Only think I don't like is that if I get a hard code for say, loss of combination/high soot. I find the ARD is bad soooo I changed it. Now I fixed the issue BUT I can't Regen it to clear the code. The only way to clear the code is to have a successful Regen lol. See the issue here? So we have to call cat in to clear the code.... Kinda shitty. Weve (njt) have owned these engines since 2008.... I don't blame cat for saying FU to the EPA and dropping out.

I had one in an '05 379 and absolutely loved it. Those compound turbos could drag a mountain up the side of another mountain.

I had an 07 w900 with an 550hp acert and it was absolutely fantastic. That C15 was a horse. Only two problems it ever had was after 700,000 miles, the injectors became very difficult and had to change out the jakes twice because they kept decentigrating. I wanted to convert the twin turbo over to a single because let's face it. They are trash and even cat realized that,but to do it,it was going to run about 10,000 dollars for the conversion so needless to say. It still has the twin.

I know this is frowned upon, but we run a 4 2008 sdp petes, gave usual trouble, But have all been deleted, Best trucks we own even better than newer 2011+ trucks in our fleet(isx’s). Also it shocking to see how clean they still burn with emissions gone

I have a 2007 c15 acert. I put 1,700,000 before overhaul. To be clear. My engine didn't broke down on me. I did the overhaul because I though it was time to do it. It was running like a champ before overhaul.

Josh, I'm a nut for durability and longevity videos. I go crazy over the stuff you post about million mile and high hour engines and internal wear. If you could someday do a video about Cat generator/truck engines with crazy miles and 40k+ hours and how they got there, how they were maintained, and what parts were still original. I've read about Cat generators that have run basically non-stop for years on end, on islands and places with no other power source. Love your stuff immensely. Take care and thanks.

I owed a 2001 C-15 " 6NZ " best engine I ever had in over 30 years truck driving since 89. Wish I still had it. Thank you 👍

Josh is awesome. He really knows his stuff and can explain it unlike other people who just show up to collect a paycheck.

ACERTS were not bad.....but yes the actuators were a pain in the butt. The combo of high compression and high boost from the compounds plus the added complexity hurt reliability. Reprogramming those big block engines changed everything.....they run HARD.

Much respect for the reasoning. Learn so much from you even tho I have a Detroit motor in my truck.

As an old technical writer, bless you for explaining the acronyms!

Long story short, keep in mind my mileage is Canadian numbers. Had a C15 1994 475 hp, trouble free 8-9 mpg pulling 140,000 lbs. Bought a new Pete 2005 C15 550 hp same job same weight. Always in the shop we called them Vivas always needing adjusting mpg? 4.5-5 so less pollution but you burn way more fuel. Let’s not even talk about the junk out there now. That 1994 is still hauling Stateside my neighbour bought it, no issues regular maintenance. I sold it with about 850,000 miles and only did a bearing roll in. He’s well over 1 million miles and she’s never been apart. Now that was a motor.

Of all the videos I watch on RU-vid. I feel like I get more information and knowledge from your videos than any other. As a owner/operator of a c-15. I really appreciate you. Thank you for the information that you share.

That’s why I’m sticking with the 6NZ and 3406E

I think it’s a great Engine, you can’t beat that 60lbs of boost.

I'll stay with a 425 mechanical catterpillar thank you

We are running the ISX 15L Cummins at work we had a VGT turbo seal failure that sent oil into the scr/dpf just after a passive regen (thats the dealers thought). The fire department showed up and ripped the whole system out from under the truck and hosed it down. $32,000 in part (needed turbo to the stack). The insurance company totaled the truck. Now after watching this video I wonder if a plugged blow by tube was to blame for the turbo seal failure. Thank you I will have to look into that on our other trucks

In 2007, getting ready for 2010 EPA regulations. EPA came to town with their advisory board. Meeting: They said that Cat has to meet the upcoming 2010 regulation when fuel is contaminated. Our refineries do produce low sulfur diesel. But thru pipes and storage tanks, sulfur content does go up. They (EPA and their party boys) refused to answer the question posed = "What are the contamination we now need to design and build for???" No answer. So they left for Chicago tourism on the USA tab. I had wanted to install co-generation off of the exhaust manifold in the C11 thru C18 engines. This provides 6% to 12% increase. The 2006 ACERT had already increased milage to 6.8 MPG from 6 MPG on C13 {as i remember} while providing no soot exhaust. The wiring harness - keep these at stand off, away from trapped heat areas.

Thank you thank you for having a loud volume. Makes it so much easier to listen in a loud truck. 🤘

I had a PDI tuned C15 Acert making 700 hp at the flywheel that I finally rebuilt with just shy of 1 million miles due to the head gasket letting go. It was a good engine. I think the only thing we did was update the rocker arm studs when one broke, other than that it got serviced every 10,000 miles. It got worked hard too pulling tri-axle grain trailers grossing 94,000, and over 100,000lbs in the fall through spring. The PDI tuning added over 1/2 mpg, but it was still down roughly 1/2 mpg compared to my old 6NZ.

Had a fun IVA fiasco the other day on a BXS. The #1 IVA was sticking intermittently but it would stick even without oil pressure (control valve open). It also was staying open just enough to cause a miss with little to no white smoke. But also the miss wouldn’t go away when backing the IVA completely off. Found the problem by backing the IVA off while the engine was running (which would make the miss momentarily go away). Retaining nut was intact but the o-rings on the cylinder were shot. Same engine, another tech had backed all the IVAs off previously and readjusted them. It had an intermittent ticking and sometimes knocking noise in the top end. The noise came in when the IVA control valve was closed. All the IVAs were noisy but disconnecting #4 made the most dramatic reduction in sound. I didn’t see the retaining nut for the foot falling out like you sometimes do, so I assumed an o-ring failure similar to #1 was taking place. Backed it off and very quickly learned that the slave pistons will come out all the way if there is no nut in there at all. The foot cocked sideways and the rocker arm had no way to return. The piston pushing back up on the valves made short work of the rocker arm…

It's no wonder Cat practically threw their hands up and said Screw It and walked away from the the trucking scene. I don't think the EPA can be said they don't know what their demanding. They've had too consistent a track record of getting the results they've accrued.

Thanks for all you do with these videos man! As someone who just bought my first diesel pusher motorhome (2005 C7) and immediately started regretting the purchase after all the people online trash talking it, it makes much more sense now that my CAT should be fine with just proper maintenance.

I run an MXS purchased in 2014 it had inframe done just before purchasing Only engine problems I've had was an injector and replaced the IVA connectors myself as a prevention. 7.1 MPG average since ownership Only get 40 PSI in boost Put straight pipes which reduced my EGTs drastically. Great engine so far anyway.

Josh. Thank you for your support and giving the great information you share.

I would take a C15 Acert non dpf engine without question. They were the last million mile engines in my opinion. Have several at work with over a million, heads have not been off them. Now the Acert dpf engine will bankrupt you.

All i can say is my last C- 15 Acert had well over a mil miles on it and one overhead @ 534g and she was as clean as new because i know😎😉 how and what she needed to keep her fit! And we had. 7 C-13 engines that were very awesome pulling heavy haul all there lives to at least a mil each! But i will take A 3406E anyday 🤘🤘🤘 Cat power forever here!

Thank you for all this info, it’s vital for me cause I own a C-15... Thanks again!

Thanks ive been a truck mechanic for 30+ years, and working for fleets i don't get into this till they warranty is long gone. And cat has always been bring it to me. So it gave me a reason to hate them, ie im pro Cummins. Until they brought in this emission bs. Anything after the N14 sucks.but i was always impressed by their c7, extremely good on fuel, but had the problems like every other engine in the day. And you just explained everything to me. Thanks!

CAT has been out of the heavy duty truck market for over 10 years! Those engines are classified as classics!

So basically, it’s the government’s fault… no surprise there. Just like everything else we’ve ever dealt with haha. Great video josh! Love listening to your lessons on stuff. So interesting

Outstanding explanation, sir. Definitely a better explanation than DPC modules give. I do, however, have one small correction- NOx is representative of nitrogen oxides, not nitrous oxides. Nitrogen oxides are emissions, nitrous oxides belong in your drag car.

Love my 1996 3406e👍🏾

The purpose of EGR is to add inert air to the combustion chamber to lower the oxygen content which reduces NOx formation. This can also be accomplished using water injection.

Your one of the best RU-vid channels I stumbled on researching c15s

Good stuff to know. I had no clue what ACERT meant on my 04 C7

My acert outruns everything I've come up against so far. It's a stock 475 acert with a 625 acert, iva delete tune. The thing is AMAZING. 104,000#'s up a steep hill @ 38 mph. The hill is a mile long i can't tell you what the grade is.

Love watching these cat videos I don’t even have a truck bus rv or excavator but just carry on watching 👍

I can listen to you all day man... your knowledge is incredible.

Would love to find a Cummins break down like this. Excellent video!

We like the Acert engines on the farm, more reliable than a 2019 D13. We make 55psi on our 475hp c15’s

Thanks epa for making the diesel engine so overly and unnecessary complicated. I agree with the statement I just read in the comments section. Josh, you would make one hell of a teacher. Great job on explaining in this video!

The amount of bs I get for loving my ‘06 Pete acert the way it is and not “you need to single that POS and flash it” is insane…

That is by far the best EGR system ever built in my opinion pulling exhaust after the DPF system it was brilliant

Great explanation. I remember when these came out. It's too bad the epa didn't leave them alone, 02 seemed to be the best year for truck engines. Thank for the video.

Sounds like I didn't do too bad after all. I bought a 2004 Peterbilt 379 with a C15 Accert newly rebuilt (gold package) with 1.3 million miles on it and it runs great.

I have 06 nxs c15 acert. No complaints. LOVE IT. Very mechanically friendly engine, 9 sensors and twin turbo. Rebuild ones because oil cooler failure it took me my 40 hrs to clean oil/coolant mud out from inside. Old saying "Don't fix while ain't broken" Wrong. When broken will cost 10 times more. Fix it b4.

So... the solution to improve and fix ACERT engines is: GET RID OF CALIFORNIA...

I have been a cat fitter for 40 years in Australia I’ve seen lots of changers Over the times. Biggest change I noticed is the quality of the fitters. You should run classes ole mate.

Fantastic job of simplifying the complexities of the BO administration's EPA IW. ( Infinite Wisdom)

Honestly, the ARD head and that system in theory was a really good idea. Compared to how everyone else did it, injecting extra fuel into the cylinders, which always leads to some fuel dilution, possibly cylinder wall wash, and high heat in the cylinders. Doing it after the engine basically avoids all of that. Avoiding EGR for as long as they could, and then when they finally did, deciding to pull EG after the DPF was also a great idea. Gotta give cat engineers credit for all that. Not sure why they couldn’t improve the ARD head and make them reliable though. Wish they wouldn’t have stopped producing truck engines.

Stumbled across your channel got immediately glued to it subscribed very interesting thank you !!

I have a KCB in an 06 Wanderlodge. It is pre emissions and was probably built in 04 or 05. In a 50K pound bus it performs really well but is a little thirsty. I have a friend that is a CAT certified mechanic that works at the local CAT shop. She said that they were pretty much bullet proof, just keep up with the maintenance. I'll never wear it out. It will last longer than I will. My son can play with it when I am dead and gone if he wishes.

Let me just clear this up. Truck engine do not release nitrous oxides in there exhaust. They do however release nitrogen oxide. NOx.

They hate it because the cat acerts it’s dominance

My 2005 C13 has been pretty good to me. Thank you for posting I’m going to install a switchblade turbo this fall on it.

Thank you I was looking to get a used glider with low miles that happens to have an '07 Acert. Currently I'm driving a 97 Detroit 12.7. I'm going to stick with it.

Had a c15 2005 Acert that ran every day doing local heavy haul. The real problem was the intake valve actuators. Even the mechanics got the joke of replacing the intake valve actuator when the engine light came on. Besides that the engine was one of the best motors that I have run. It was finally rebuilt with 22000 hours and approximately 430,000 miles. The real only way I knew that something was wrong was the boost would fall from 52psi to around 25-27 psi. I personally liked the motor if they would have a permanent fit for the intake valve actuators. Thanks for going thru this motor.

We had two ways to go. First was straight egr. The second was High Volume Low Pressure (HVLP) with the two turbos. This provided a much lower intake air charge than a straight egr system. Unfortunately development time was cut by a year and a half due to budget issues so we had to choose one path and focus on that. Once tier 4B hit we added urea (def) to the exhaust and dpf filters as an after treatment. The filters from the supplier had issues, the ard heads would crack, the after coolers would form hydrochloric acid due exhaust gasses combining with water vapor in the air. Normally that wouldn’t have been an issue as the temp was too high to cause condensation. And of course the VIVA system which worked but really beat the valves to death. It’s too bad further development didn’t continue. I believe with a common rail (higher fuel pressure at injection) and laser cut injector tips would have created much better atomization of fuel help with emissions. But idk I could be wrong.

I ran a c12 and a c13. The difference was night and day between the two. The c13 had way more torque. It pulled way better on hills. I personally liked the alert engines.

I run a mxs 550 50 psi boost easy I.v.as. deleted awesome engine pulls awesome and gets mid 6s for fuel mileage love it

Doing a C18 in a compactor for NRS/EGR cooler failure resulting in hydrolock. The new C9.3B does away with EGR, but uses more DEF. In the machines, they have the ARD hammered out pretty well

2005 KCB C13 and I'm very happy with it but I'm having my first problems with it in 3 years other than an oil cooler I replaced about 1 year ago. The problem started off with a IVA code that was fixed with new injector harnesses. After installing it that code went away and a new code for the oil pressure sensor came up. Replaced it and pressure on the dash dropped from 80psi to 50 and code went away. but a new code popped up for barometric pressure sensor and IVA oil pressure not responding. Replace barometric sensor and it's code went away but now I'm left with the IVA oil pressure code. Of course it doesn't pop up immediately upon start but only after it's self-test approx. 30 seconds. I'm sure I should just replace the pressure sensor but while I've got the valve cover off again I'm wondering if I should address some other problems. I'm getting some darkening of fuel and a very small amount of oil (less than an ounce between oil changes) getting in the coolant. Should I be looking at injector tube o-rings or just injector o-rings and an overhead. I spoke to the closest thing we have to a CAT mechanic in this county and he said chain failures of sensors isn't uncommon so I'm crossing my fingers on that. I should mention that I had to take the rear IVA off to clean out the plug for the new harness. Engine is tucked under the firewall so I couldn't get to it without removal. I kept the bolts in it and put it back on in the same position it came out but it did seperate a bit during removal. Is there an o-ring in there that might have fell out? If you don't reply I understand. This isn't a repair forum but you're only guy I trust to know his stuff on these engines that I know of.

Josh you are a great mechanic and have a ton of general knowledge thanks for sharing

Great video A Ape, I like your objective sarcasm on what cost the engine manufactures and industry billions. It's no wonder why Cat stepped away from over the road applications. The EPA continues to bring on the demise of the diesel engine.

Already drove a C13 KCB in the past and they where reliable and fun to drive. Not to mention they where torque monsters. I've often seen theses little kitty cat loosing ISX15 (anyway, everybody knows that Cummins is scared of eight so they loose all strengh on the foot of the hill) and DD15 in the dust. But like the new trends say, we got to get rid of what's reliable so we can earn more money with fixing stuff

This is really great info, taking notes is making it grueling but I'm learning alot

Love the C15 acert the sound of it sounds mean even with out straight pipes

You are very intelligent young man. Thank you for clearing that up.!!!!

All they needed was independent VVT for both intake and exhaust sides like the one used on every modern gasoline fed four banger nowadays, DPF, DEF and maybe a small[quick spool, off idle high boost] and a big[high HP top end] turbos in series. OR one super expensive and complicated VGT turbo to keep parts count down.

Many of the problems with the IVA's were due to cat refining their manufacturing process from creating different model IVA's to just manufacturing one base IVA for the C13 and C15. I believe they later reverted back and began manufacturing multiple models.

We had more problems with the Iva’s cracking the Jake housing than with wiring.

It's not nitrous oxides btw, it's oxides of nitrogen. Completely different to laughing gas.

I always wondered why they used the ARD head vs the DOC that Cummins and detroit used. I never had an issue with Avery's, pre dpf. Other than the Turbos made some accessibility issues

Well spoke and very informative..I learned a lot about Caterpillar truck engines

I prefer my 03 cat. But I did have an 07 acert. I put a heavier fuel spring in ported the in and out side of the fuel lines, so the fuel ran cooler in the lines. It jumped my milage up about 2 miles per gallon and ran so much better. Never had an issue after that. Simple fix for a better running engine.