Hello all, Im thinking about buying a 2008 Chevy HHR and the guy selling the car says that it is throwing code P0101 every once and a while. Im posting his exact words below.

"The only thing that is an "issue" with the car is that the ambient air temp sensor is going out, and sporadically causes the check engine light to go on briefly. I have attached pictures of the code and the live data of what exactly is happening when the code pops. Basically the sensor drops to nothing being read for a few seconds causing a temperature variation fault code. I haven't been bothered to fix it because I have a code reader in the car and can clear the code rather quickly - and it doesn't pop up that often. Also 2 of the TPMS Sensors are out causing the "Low tire pressure" light to constantly be on - the car has had this since I bought it. (also hasn't bothered me enough to fix)"

Is this something that should be concerning, is it pretty easy to fix? Im also going to share 2 photos that he sent me.
I just dont want to buy a lemon.
Thanks for all your help and recommendations.
Jason

 

The MAF is the problem. Does it run bad when it happens? How long did this guy own it? Why is he selling?

 

The ambient temp sensor does not cause any codes that I ever heard of. If he has a code reader in the car he can provide a code NUMBER.
If you mean the intake air temp sensor it is part of the MAF. Is the MAF securely plugged in? Are there any leaks in ANY of the air ducting.
P0101 has to do with the MAF not agreeing with the computer's estimate of what it should be.
Is there an oiled air filter on the car? They can cause the MAF and IAT to die when there is too much oil.
It is not advised to clear codes, most will clear themselves upon repair. In the mean time all of the OBD2 testing has to start from 0, and the EVAP testing can take weeks to complete.
A 2008 model needs to have the firmware in the RCDLR updated or, if there is a battery disconnect for any length of time the TPMS will read ---- and you will not be able to reset the tire positions.
The ambient temp sensor is on the frame horn under the bumper cover on the passenger side.
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The guy has owned it since 2021. He said the only thing he has done, is replaced the intercooler. He said that when the code pops it never effects the cars driving. So he said he just checks it with his reader, and then resets it, he said it doesnt come on alot. He also said that the guy he bought it from had upgraded the MAP and MAF sensors to help increase the horsepower

 

That means it has a "tune" maybe the GM turbo upgrade or some other. Look for a sticker on the fuel filler that say 91 octane REQUIRED vs recommended.
Replacing the intercooler could cause the P0101 due to bad connections in the ducts, they take special clamps that need torqueing.

 

I had recurring p0101 issues, twice. I am skeptical that the car drives fine. Even when it was pending for me, I would lose the turbo. Both times the fix was a new air filter.

 

What code is telling him that?

If that "ambient air temperature" chart is reading the temp sensor under the bumper, I'm not sure the ECM cares. I thought that sensor was just for the driver's information.

The intake air temp seems erratic. Does the car have a "cold air intake"? Any other mods?

Careful with this one. The owner seems to like to put off dealing with even basic issues. Any oil change records? How much boost does it make?

Probably should try to find a mechanic familiar with turbo Ecotecs to look at it. Right off the bat I'd say get a compression check.