Second Opinion) Customer: I have a pp171 code on my carJA...

Hello, I'll be happy to help out with this, and sorry you're having this issue. Can you tell me the whole backstory on how long this light has been on, and about hitting something in the road? Also, which [engine](/topics-engine-chevy/) do you have? 1.4 or 1.8?

1.8

And how many miles do you have on it?

About 54,000

Gotcha, thanks. That is almost always caused by a vacuum leak on these, they are quite known for it. How does it idle? High or rough or anything abnormal?

It didn't seem to be idlng rough

Ok, the first thing to double check, especially since you just had your oil changed is to make sure they got the oil dipstick and the oil fill cap back on properly, that's certainly once cause, and being that it happened after the oil change, could be. So make sure those are seated and not twisted on wrong in the case the of the oil cap first.

OkI was smelling burning oil while driving

That would be an easy fix for sure :) I would certainly check that then to start. Let me know what you find and we'll go on from there. Feel free to send me pics of anything you like as well, the fill cap or anything needed.

They seem to be fitting properly

Ok, bummer. Can you see any oil residue anywhere? If you were getting a burning smell it could have just been a small drip they missed, but best to double check that. The next step would be to check for vacuum leaks around the intake and pcv hoses and other vacuum lines. You can do this while the car is idling with a can of brake cleaner. You lightly spray it on there and if the idle changes anywhere you spray it that's a leak. Obviously you can visually inspect the lines as well. The main off the booster as well. If this doesn't get us anything, those also will throw that code for a EVAP cannister purge valve. You haven't had any trouble with filling the car up with gas or anything have you? Like the pump shutting off before you can get it filled?

No not reallylet's say i hit something in the street would that set a evap code

Ok, it can be just a leaking one as well. The purge valve is located up by the intake. I'm going to send you a document that shows the replacement procedure, but first just take a look as a reference so you can check it out for a vacuum leak at that point. Most of those hoses for the EVAP system are fairly protected, what did you hit and where on the car?

I can't remember what is and it was underneath the car

Well without much to go on, I would certainly recommend checking it out just to make sure nothing else got damaged. I doubt you developed this code from that, but I would check the vacuum system as recommended, especially that purge solenoid.

How hard is it to check the vacuum systemWhere on this would the purge solenoid be

It's not hard, you just do a visual inspection, then do the inspection I described above with a can of brake clean. I sent you the document with the purge solenoid location as well. Right next to the intake manifold.

Where would the 02 sensor be on this car

On the [exhaust](/topics-exhaust-chevy/) manifold.

If the problem was the oil how many cycles would i have to drive to see if the check engine light turns off

If the o2 sensor was bad would it kick on a different code

It depends on the code but for the P0171 it takes two. Yes the 02 would throw a different code.

Two cycles to turn off the check engine light

Or you can disconnect the battery for about half an hour, that will clear most codes.

Ok thank could it be cheap or expensive fix