All I can offer is this GoOgle search for "p0131". https://www.google.com/search?q=p0131&ie=utf-8&oe=utf-8

There have been 3 other citations of p0131 with p0171 in the 10 years of this forum, all of them turned out to be an exhaust leak before the #1 O2 sensor or a wet/fouled wire.

 

My P0171 Came up in my attempt to change out my stock air box for an aftermarket Airaid kit. Even with everything tight and installed correctly, the code would be thrown at the first sign of throttle given to the engine. Even Airaid didn't know what the problem was. Back when I had the issues. Nothing I did could fix the issue, and it was a dry filter. So, I had to sell the unit and go back to stock, haven't seen the code since. Isnt yours an 06 2.4 as well? do you have an aftermarket air intake system?

 

Thank you all very much for the input. I have a brand new oxygen sensor in the car, and still getting the codes. The wires looked fine. Is there a way to tell if the flex pipe is leaking? I dont smell exhaust under the hood, and it looks good.
My thoughts with the fuel injector-if one is not working properly, wont that cylinder run lean? Wouldnt that throw the code also? I am not trying to be difficult or argumentative. I am just trying to understand what is going on.
Again, thanks for all your help. Also again, I wish I had dropped a SBC in. So much simpler to understand...

 

I thought you already messed with the injectors. That would be the end of my list, they don't go bad that often.

 

It may be a good idea to remove the downpipe and closely inspect the flex pipe. Doesn't seem too difficult, unless the fasteners are all rusted up.

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

 

Ok, folks, let's focus, Lee3333 you might not see the crack at the flex pipe , if it is cracked it will cause your lean condition, I drove all the back from Florida with a cracked flex pipe, I repaired the damaged part , codes gone.
We suggest this because the injectors don't usually cause problems. They are much more expensive to replace.

 

Hope I didn't step on any toes. I moved the code-related posts here, and left the waterpump-related posts in Lee's waterpump thread. Deleted a few posts about confusion. Now we're rockin' and rollin' again!

 

Thanks RJ. Just trying to keep similar posts in the appropriate threads.

By the way, I did not totally remove or clean the injectors yet. Just took off the rail and cleaned the bottom part. I still have to check the top to make sure they are not clogged

From what I read, the flex pipe requires welding-not a simple fix

 

Yes, but the thread shows that's it's easy to remove, for inspection. If it's fine, put it back, on to the next item. If it's cracked, you have the options to weld, or to replace the whole downpipe.

Is there a way you can get an extension for your inspection? Even if you could find the fix tomorrow, your inspection is in, what, a week? And you still may need to complete some drive cycles before all systems are 'ready'. You are referring to a smog inspection, right?

 

I replaced the flex pipe it's part of the catalytic converter, 5 fasteners, easy fix.

2005 2006 2007 Chevrolet HHR Catalytic Converter flex down pipe 2.4 ** NEW ** | eBay