P0172 Code- Help Please
 

I'll do my best to document through the process of my repairs thus far in attempt to clear this code. I've searched the site, and there are bits and pieces scattered across the board.

Looking for some help with a P0172- rich A/F.
Car is a 2009 HHR 2.4L Automatic w/ 70k on it. It's my wifes daily driver. She only drives a very short distance to work everyday (not even a mile), but most often we drive my truck wherever we go.

Car has ran fine, but she mentioned she had a CEL and that the remote start wouldn't work. (Due to CEL light)

P0172 code info https://www.obd-codes.com/p0172

Pulled code, showed a P0172 code, and a P0172 permanent code.
Cleared code, added fuel conditioner.

Code Returned.
Checked for exhaust leaks by placing rag over the tailpipe and listened for changes in exhaust. I could not hear an exhaust leak when I did that. (I was working alone, so I may recheck that again)

Checked for vac leaks in engine bay by spraying throttle body cleaner around all vac fittings and location in engine bay. No change in idle to indicate a leak.

Cleaned MAF sensor. Cleared Code.
Told wife to follow procedure to erase permanent code.
https://www.autoserviceworld.com/car...ermanent-dtcs/

Code has returned. I just cleared it again yesterday, and I'm starting to worry this is deeper than thought.

Any thoughts as to where to look next. I found a few writeups on here about the evap canister? that near the rear of the car???? I'm a bit confused as to where this is located and what needs to be replaced.

Or is there a better way to diagnose the flex pipe?

Could it be 02 sensors? (She had an 02 sensor code a really long time ago, that was cleared and never returned)

Thanks for the help, I'll continue to work through this and happy to share the entire process for the next guy.

Check the flex pipe for cracks

Here are some more thoughts
https://www.yourmechanic.com/article...-blake-griffin

Do you have any tips on doing this? I didn't visibly see any. And when I covered the tailpipe with a rag, I didn't hear any noticible exhaust leak...

Thanks for this RJ. Any tips on what the fuel pressure should be at?

From the link you posted from OBD codes

Inspect fuel lines for cracks, leaks, or pinches Check the fuel pressure at the fuel rail Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced. Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)

Read more at: https://www.obd-codes.com/p0172
Copyright OBD-Codes.com


https://www.chevyhhr.net/forums/how-...ex-pipe-31536/

50-60 psi. Do you have an oiled air filter? Have you replaced the spark plugs?

Cleaning injectors costs as much as replacing them.

Out of these possibilities my guess would be the EVAP purge valve. That is the one under the hood. Disconnect both pipes and the electrical connection, blow into one side. If it is open replace it. They are less than $20, so you might want to just do it, Duralast/AutoZone PV443, similar number at other big box stores.

https://cimg5.ibsrv.net/gimg/www.che...ec95ca2f26.png

I do. But it hasn't been oiled in quite some time. I've been using K&ns since eons. I don't overoil, and always allow to dry.
I've cleaned the maf recently though.

Ahh, the evap master Ive seen posting in here has spoken. Thanks bud! The evap is the one that has really stumped me.
Can you be a bit clearer on where this purge valve is or what it looks like. Maybe a link to a diagram?? I'll just swap it out for $20 without question.