code p0171, vacuum diagram needed?

2008 CHEVROLET IMPALA

257,635 MILES • 5.3L • V8 • 2WD • AUTOMATIC

KEITH ERICKSON

MEMBER
1 POST

I have a engine code p0171 and I can't find the leak anywhere, I was asking if I can get a diagram of the vacuum lines so may follow them and hopefully find the leak.

Oct 24, 2022 at 11:55 PM

STRAILER

✓Experienced Mechanic
55,214 POSTS

So, what happens with these engines is the EVAP tube has O rings that go bad and allow a leak. This problem can also be caused by a MAF sensor that is off a little which leans the engine out. Here are three guides that can help us fix the problem. Make sure you check the engine when it is cold.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

and

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Here is the location of the MAF sensor so you can check it out. Make sure the air tube is secure with no leaks. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Oct 25, 2022 at 4:37 AM