Lee3333

I figured that-but it was late last night and I had to get to bed early-on my way to 3 back-to-back medical appointments now, so I did not have time to do a search. I am not trying to be lazy-just rushed

Lee3333

Just changed my MAP sensor. Now just down to 2 codes-the PO121 (throttle) and CO561. Have to drive it now to see if those 2 go away, and if the MAP helped with the T/C problem. Everything looks good on my throttle body, and I would hate to have to buy a new one if the PO121 persists. In spite of all this, the car runs great. Have had these codes for years, though never to the extent of the constant CEL.

Lucky

This thread may help you with your tps code.

https://www.chevyhhr.net/forums/problems-service-repairs-42/i-have-2006-chevy-hhr-lt-2-4-a-49065/

Lee3333

Took my daughter to school-12 miles-after changing MAP and NO CODES!!!! Then when I drove home, dreaded CEL came on. Still no T/C light, though. When I got home, same PO121, but now a new code-PO326 knock sensor. I reset it, and will see if the 326 comes on again. But first, I have to try cleaning out the throttle body. Any suggestions to a good way to do it? I know they make a special MAF cleaner, and I think I saw one for TB's. Is regular carb/choke cleaner ok?

db/sb

In a word....NO! Carb cleaner leaves a solvent behind that to some extent fouls the MAF sensor. And its solvents are too harsh. MAF cleaner is like a electrical cleaner. Very clean, evaporates. You can use MAF cleaner for it all, including cleaning the TB.

Lee3333

Got you. I was going to get both MAF and TB cleaner when I go out in a few minutes. Have to fix it fast because I only have a few days left on my temporary inspection.

Is there any difference between the MAF and TB cleaner?

db/sb

Unless your TB is really dirty you can use MAF cleaner on it. MAF cleaner is made for electronics, TB cleaner is not.

hhr11

Like db/sb says never use carb cleaner on the new TB's etc. They have plastic parts that can actually be ruined from the solvent in carb cleaner. I used to use cc all the time until I found out the hard way.

Lee3333

Thanks, guys. Just picked up both cleaners and will do it tomorrow. Also threw a bottle of Chevron Tech cleaner in the tank

whopper

Lee333 - I threw a bottle of that Chevron cleaner in the tank as well - but man, it was a tight fit!!!!!!