There were no other codes. Only other code was a generic seatbelt code (B0081-71) in history, but seatbelt system doesn't really gave anything to do with fuel trims

Hmmmmmm, I remember it did say "GM Genuine" right on the box. It was "sold by Amazon" rather than a random 3rd party seller, so I assume it was a legit product. I know 3rd party sellers are the highest risk for the counterfeit stuff, so I try to avoid them wherever possible

Anyways, I'm just glad it was just a faulty MAF sensor (cheap and ez to install) rather than something more expensive/involved 😂 (...such as replacing a fuel pump)

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Enjoy the ride!!

 

Just in case anyone stumbles across this thread, here are some pics of the old (faulty) MAF sensor:





Looking at it more closely earlier in the kitchen, I notice the sensing element (the thing with the large "orange" section) seemed to be slightly bent downwards

Seems to be touching the MAF sensor casing (on the bottom), I wonder if that had anything to do with the over-estimated airflow. For what it's worth, I notice the aftermarket Hitachi sensor I bought had a slightly smaller sensing element, and all the sensing elements were nice and straight

 

The part number is also different but it does fit an HHR

 

I'm now wondering if I got a used one and just didn't notice back then

At the time I was trying to fix a P0102 code so I was in a hurry to install it, when I took it out of the box I didn't see any fingerprints or smudges on it so it didn't cross my mind at the time

I've heard of people getting used "new" products from Amazon, so who knows. It's possible I got a used one and they just cleaned it up real good before putting it back on the shelf? The sensing element looks a bit crooked so if this was a used part maybe the previous customer/refunder stuck something in there and bent the element

 

It’s a moot point now, chuck it and forget about it!

 

213-4222 is part of the Supersession list. Yes it says Hummer H3, but it is correct for HHR, possibly the OE part.

 

The orange thing is the temp sensor. The way the MAF works is by heating the element then measuring the temp drop thus inferring the airflow.

 

This is plausible. I think it happened to me (with a with a completely different type of item.) Amazon accepts returns readily and I don’t think they have a terribly robust system for inspecting returned stuff before it goes into stock. And we all know there are snakes who will put their old part in the box and return it as new.

Along another vein, I once had my trims going crazy, and it turned out the MAF sensor had what I think was a little piece of cottonwood fluff stuck in it. Moral of story, with trim trouble, always inspect and clean the MAF sensor, even if you just did it days ago.