Envoy/ Chevy Trailblazer Rough Idle With P0171, P0300 And P0160 / Intake Gasket Replacement *FIXED* 

Sounds like you're on the right track, the intake bolt behind the alternator will most likely give you the most difficulty, some people end up loosening the alternator in order to remove that bolt, but just take your time, you can do it.

Much respect for the big ups, appreciate you taking the time.

you're welcome Juan

Much thanks, not too hard of a job, if you have or can get a 1/4 inch 10 mm socket with a flexible extension, it will help to make the job much smoother, the bolt behind the alternator took the most tine. you can do it.

much respect Sir, I am new to the video creation part of this, but I do my best, and I'm learning as I go. the whole aim is to share my knowledge with whoever needs it.

@EuphoricNails, that could be just about anything from a bad alternator, an interior light that is not cutting out once you cut the car off, like the glove box or trunk light for example, or even the alarm system like you mentioned. Best thing I suggest is to perform a draw test, this involves using a test light to connect between one pole of your battery and the wire, the test light should illuminate once connected, you would then remove one fuse at a time to see if the light dims or goes out, in either case, once you see a change, that system should be where the issue is. You can find videos here on RU-vid how to do it, good luck, and let me know if you were able to figure it out..

@TERRELL SCAIFE you're welcome, always good to hear that my videos are helpful, good luck with that.. keep in touch, let me know what you find...

Yeah, buddy, your video gave me up a point to start. I discovered the leak coming from the air filter box tube that connects to the upper intake manifold. so I’m gonna put a little silicone on there and see if that works if not, I’m going to the junkyard to get another one because I already rebuilt the engine, new piston, rings, new piston, heads, and all those Val cover, and intake. Manifold seals were replaced. New spark plugs so I was a little puzzled on how could I be throwing the P0171 and P0300 so I appreciate your video you gave me a point to start and I think I conquered the master thank you buddy

@@terrellscaife2411 You're welcome man, I see you put in some serious work on it, so you gotta get straight..

Yeah buddy, I consider myself an advanced Shadetree mechanic, but on that car I did in frame engine rebuild rebuild the front suspension and I replace the front differential so after I did that repair on the The air filter box that tube goes to the upper intake manifold on the upper intake manifold, where there is a you will see a split or they did the mold injection from the bottom part to the top part. There’s a line there where I was getting my leak so I put some silicone on there and I did some testing and did some testing so it was a pending code but I was running a car for a little bit, but it did not turn into a active code. so yeah, I work on everything from lawn Moore up to semi trucks construction equipment whatever but I don’t know everything but like I said, your video helped me out a whole lot and I really appreciate that

@@terrellscaife2411 keep at man, you're on the right track, if you have a question just ask, will try to help best possible..

Hi Engels, the 4.2 don't use an actual pcv valve, but it does have a pvc system, are you having issues with the crank case ventilation on your truck?

also much thanks for subscribing, I appreciatey you doing that.

Obviously there is a bad fuel mixture and my trail Blazer truck is using a lot of gas. THAT COULD BE HAPPENING?

@@engelspavelgonzalez91 have you done a diagnostic on your car?

If you mean the last lower one at the back, I used a 1/4 inch drive socket and ratchet..

@@thediyyardie7192 I Manage to remove it really was not that hard.

@@angelf9800 great, just takes a little patience..

Having the right tools,extensions & patience is paramount when working on an engine or anything for that matter! Great vid my friend very useful!👍

What year is the car you're working on James?

It's a 2003 with 205k. I was able to get to the bolt after taking out the alternator. Some critter nested in the engine and chewed the wiring harness behind the engine. So I'm having to rewire the harness where the connector goes from the coils to the injectors. Major nightmare. Thanks for your video. @@thediyyardie7192

it has a PCV system not a direct valve..

I also replaced the fuel filter

Hi Debra, I noticed that you said that you don't believe its the fuel pump, but has your mechanic checked out the fuel pressure while the car is running smoothly, and at the time that it is acting up?

@@thediyyardie7192 it is a friend who has looked at it who has been a mechanic for 40 years but has not enough experience with newer model cars and doesn't know much about the different ways of checking for problems. He hooked a pressure Guage up to the car while it was running but couldn't check it while driving since he doesn't know how. I've read about so many people who were told to get new pumps but when they did a few days later they had the same problem. There is a list of things like fuel pressure regulator, fuel level sensor in the tank, and other sensors that can cause the symptoms mine is having. But the main reason I don't believe it is the pump is because it always starts up immediately when you turn the key and when it starts to sputter if I take my foot off the gas pedal it will idle smoothly. All the symptoms I've seen from others have not happened to my car which is why I'm so confused. The pressure on my car was 40 psi running sitting still which is another question I have. Everything I've managed to find on pressure says 35-65 psi is the range for most cars depending on manufacturers specs which I can't find on the internet for my particular car.

sorry to hear that, but yes there has to be a leak someplace else, there's a vacuum connector that should have a rubber stopper covering it towards the right front of the intake manifold, verify the rubber stopper is still in place. also did you try the spray test to check for leaks?

@@thediyyardie7192 I believe the rubber stopper is still in place. I do not have a rough idle except for maybe 10 seconds at cold start up.

@@paulhawkins1460 ok, so what are the codes that you're getting exactly?

@@thediyyardie7192 p0171, and p0300 however the p0300 is not all the time.

@@paulhawkins1460 two things, you didn't answer about if you tried the spray method to locate a leak; and also have you tried cleaning your mass air flow sensor?

The issue wasn't with the Throttle Body on this car, it was a worn intake manifold gasket..

​@@thediyyardie7192I think he's referring to your accent when your saying throttle body?

@@justmy2cents_ oh ok, I missed that one, but its all good, I'm sure everyone got what I was saying..