2005 Silverado Misfire p0300 

Thank you Keith. Good job. As always, I appreciate your videos. Have a blessed and safe night.

The master at work. You really make this look waaayy too easy. My biggest take away from your videos is to trust my test results. I second guess myself way too often. Especially when the vehicle has already been to a few mechanics who haven't resolved the customer complaint.

Thanks for the time you take to make these interesting videos.

Always awesome watching a master at work!

Keith, Great video and diagnosis. Thank you! God bless Paul

Taking a trip down memory lane!!! As always, great video and diag!

And another diag just sitting in the car without having to pop open the hood. Excellent Maestro. That must be a great feeling

Great work Keith. Always enjoy your videos and the way you educate

Quick misfire diagnostics! I like it! Good Job!

Thanks for all you do.

I don't even wait to watch your videos, I just click the thumbs up as soon as I get here. You da Man, Keith!

I was sitting there trying to think of what would cause just one bank to misfire ... and an o2 sensor wasn't even on my radar! So many things to keep in the brain on modern vehicles, I forget the basics! Thanks for rattling the brain cells around a bit, Keith. 😁👍🍻

Another great lesson for the great man himself. Thank you

My man! Thanks for adding value to the industry 😉

Nice job buddy, you work your magic so nicely. I did auto motive work for 13 years up until 4 years ago I got hired into the rail road. I wish I could have worked with someone as nice and as teachable as you. Your a great man and I appreciate you & your video. Take care buddy!

Great video thanks brother. I like the thought process and the tools help. Keep up the great work see you in the next video thanks again brother

Quick and dirty straight to the problem .... great tip sir

THIS IS A GREAT VIDEO KEITH I KNOW YOU HAVE A GOOD EYE FOR THIS . I WOULD LOVE TO SEE WHAT ACTUALLY HAPPENS WHEN THAT 02 SENSOR GOES IN . THAT BOSCH ADS 625 HAS SO MUCH INFORMATION THIS TOOL IS PUNCHING WAY ABOVE THE AVERAGE TECH'S WEIGHT CLASS IT'S LIKE HAVING A GUARANTEED FIX . IT'S NICE TO HAVE TWO TO THREE TOOLS IN ONE RIGHT THERE WITH YOU AT ONCE . THANK YOU SIR !

Awesome, can’t wait for part 2:)

Fuel trims are a awesome tool for diag O2 problems. I did a old school ranger last week that has been running like shit for 3 years right after a engine swap was done. 5 garages couldn't figure the problem out and lots of wasted money was spent. 5 min is all it took me, soon as I seen the fuel trims and the O2 sensors readings I knew what the problem was. They had the O2 sensors connected wrong. Great Video Keith

Thanks for the video, you make it look so easy

I bet most of us were thinking, vacuum leak at intake manifold, but professor Defazio proof me wrong again. Thank you Keith.

Great vid Keith - good reminder to evaluate O2s per bank if whole bank is misfiring!

Great job again like always

I just had the exact same issue! Got me to the right place, in my case the pickup ran worse with the new 02 sensor installed! The cat was plugged on bank 1

Man... 6 minutes... That's even _with_ making a video! That's pretty solid.

Keith, awesome and great video/info thanks for sharing brotha.cheeeeeeeeers

I never had a o2 sensor last so long until I moved here. I swear the lack of road salt keeps them alive longer. I need to change those on a 06 Sierra just as preventive maintenance have them around somewhere haha. They all create multiple misfires when they fail on these

Misfire on one bank, O2 sensor check for the win. Thanks!

Thxs Keith pls come back great video, my 06 dakota v6 84,000 miles is having misfires,but no money light,has new 02's and plugs,coils soo ?

Was it running smooth until it reached closed loop and then started misfiring? Is that why you went right for the o2 sensor data? Or did you notice all cylinders on one bank were misfiring which led you to the o2 sensor data? I just ask because I know sometimes you perform the diagnosis and then record the video. I like to retrace your thought process during diagnosis. Thanks for another great video.

Good video. I must say that here in Vancouver British Columbia, if you are a shop owner and you don’t have a Technician that can figure out something like that, you may as well close your business.

is possible that a HO2S B1S2 cause a misfiring on a 4 cylinders 2.5 engine??

Thanks for the video.

My 2004 8.1 chevy 2500hd is giving me p0300. Did the fuel system test today . I have 58psi key on not running and 61 psi at idle. Seems good. I have had 3 mechanics charge me alot of money and they can't get it. Could it really only be an o2 sensor? Is there a way to test o2 sensors? Ohm meter?

What kind of scan tool do you use?

thanks great vid

The power of knowledge.

Great video thank you! !!!!

did that truck idle rough at idle?

Nice video brother. Question what type of scanner is that

for a while there i was thinking, hey! a seven cylinder engine!

So this will cause considerable power loss ?

I understood the explanation I miss to know the solution in the end if video ? 😊 Please, anyone could clarify the fix !! Is it by changing the o2 sensor bank 1 or what ?

Quick and easy! Now question is what makes an o2 sensor fail. Rich condition, why rich? No spark. Awesome deduction as always.

How did you fixed?

Would unplugging the o2 sensor be a valid test? Force that bank to go to open loop and see if the misfires go away?

Love it, Keith!

I have a 02 chevy silverado 5.3 vortec with the p0300 code light on and I don't know what could it be I have had the spark plug wires and spark plugs replaced 6 months ago so I would doubt that's the issue any help would be greatly appreciated.

Thankyou sir

Question on one bank a bad o2 would let the injectors on one bank stay open longer?? Causing a miss fire

Kdkdidi

They might want to check the exhaust manifold on that bank as well ... the bolts tend to break at that age

I been watching these videos for two days and nobody can find or locate the fuel regulator on a 2004 GMC yukon, I was told it was in the fuel tank. I pulled the fuel pump and it's not in the tank. It's not on side the fuel reels. Help!!!!

Would have had a po171 soon and your po301-po308 whatever cylinder we’re missing which as bank 2 I done forgot lol but The reason you’re short term went to zero when you rev the engine is because it went into open loop and when it started calculating again it went back into closed loop

I think the plugs would needed to be changed,as lean as it was running,would you tell them first,or let them choose....or you can pay me now or pay me later?...

more like a nO2 sensor =p wonder how long they drove it like that and what shape the cat is in now, yikes

nice !

I love your Chevy videos because I have one or two. Am I being bias? :)

Ch ch Chevy Chevy bang bang! 🤭

Si señor 🙌✨🛻💣💨🤦‍♂️Omw

Any update

Gas Pedal easier and safer than a shot of brake cleaner to intake (backfire.boom.ouch) to drive rich and observe 02 voltage changes. Safety first. 😉

Have only p0300 and no check engine light on, rough idle. 03 Tahoe Z71

Leaky purge valve if just a P0300 and a P0455 on these Gen 3 LS engines especially if the engine sat for a while over winter.

When's the last time you looked at an engine. Their up front

so a lean condition will cause a misfire.. Can a misfire cause a lean condition ?

👍 THANKS 🚹

Plugs and an oil change 😂 Love it!

Classic Chevy. Just unplug b1s1 that Will fix it 👍😁

i have a 2005 chevy silverado 1500 i got that code p0300 back 1/1 so i will get acdelco

waiting for the follow up

Why couldn't GM be like Ford and have the PCM ignore the O2 that's acting up

I thought GM set a 'bank rich' code when long term trim got above 20%? Or was I dreaming?

It's not a express lol

That thing must have smelled awful.

First😀

always do BOTH UPSTREAMS at the same interval

Fuel injectors..

Not an Express?? Unsubscribing!!

First

Next month clogged cat

Ksidkdkdidididiidid

So this will cause considerable power loss ?