Problems/Service/Repairs If you have a problem with your HHR, want a tip on repairing or performing a particular service to you HHR here is the place to post!

P0172 Code- Help Please

Thread Tools
 
Search this Thread
 
Old 07-13-2018, 09:58 AM
  #1  
Senior Member
Thread Starter
 
cturboaddict's Avatar
 
Join Date: 12-10-2010
Location: Collinsville, IL
Posts: 128
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.
cturboaddict is offline  
Old 07-13-2018, 10:43 AM
  #2  
Administrator
 
Oldblue's Avatar
 
Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 36,513
Check the flex pipe for cracks
Oldblue is offline  
Old 07-13-2018, 11:00 AM
  #3  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 7,808
Here are some more thoughts
https://www.yourmechanic.com/article...-blake-griffin
RJ_RS_SS_350 is offline  
Old 07-13-2018, 12:22 PM
  #4  
Senior Member
Thread Starter
 
cturboaddict's Avatar
 
Join Date: 12-10-2010
Location: Collinsville, IL
Posts: 128
Originally Posted by Oldblue
Check the flex pipe for cracks
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...
cturboaddict is offline  
Old 07-13-2018, 12:23 PM
  #5  
Senior Member
Thread Starter
 
cturboaddict's Avatar
 
Join Date: 12-10-2010
Location: Collinsville, IL
Posts: 128
Originally Posted by RJ_RS_SS_350
Thanks for this RJ. Any tips on what the fuel pressure should be at?
cturboaddict is offline  
Old 07-13-2018, 12:53 PM
  #6  
Administrator
 
Oldblue's Avatar
 
Join Date: 10-13-2011
Location: Welland,Ont Canada
Posts: 36,513
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/
Oldblue is offline  
Old 07-13-2018, 01:03 PM
  #7  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 7,808
50-60 psi. Do you have an oiled air filter? Have you replaced the spark plugs?
RJ_RS_SS_350 is offline  
Old 07-13-2018, 01:35 PM
  #8  
Technical Moderator
 
donbrew's Avatar
 
Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,694
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.

donbrew is offline  
Old 07-13-2018, 02:31 PM
  #9  
Senior Member
Thread Starter
 
cturboaddict's Avatar
 
Join Date: 12-10-2010
Location: Collinsville, IL
Posts: 128
Originally Posted by RJ_RS_SS_350
50-60 psi. Do you have an oiled air filter? Have you replaced the spark plugs?
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.
cturboaddict is offline  
Old 07-13-2018, 02:33 PM
  #10  
Senior Member
Thread Starter
 
cturboaddict's Avatar
 
Join Date: 12-10-2010
Location: Collinsville, IL
Posts: 128
Originally Posted by donbrew
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.

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.
cturboaddict is offline  


Quick Reply: P0172 Code- Help Please



All times are GMT -5. The time now is 04:20 PM.