2009 Chevy Malibu Doesn't Want to Accelerate

You will get many replies here to start selling the car, unblock the exhaust system, Replace the MAF sensor instead of cleaning it, bring it to an authorized repairer, unblock the air intake (not just cleaning the air filter), look for the oil in the gear box, check engine oil up to make everyhting so the check engine lamp does not come on again.

I will not say any of this because the others can point it out to you.

I just wish you good luck in resolving this problem!

To better understand the first paragraph of Mr. IdeaSmith click on http://www.lmgtfy.com/?q=site%3Acr4.globalspec.com+cavalier. I'm not going to read them now, I've read most of them in the past. These Google results will show you that we are about 50% helpful with car problems, sometimes more on a good day. On a bad day, well, let's just say that not everyone that has fun at the expense of others is in junior high school.

ttps://www.youtube.com/watch?v=G2ec36KfAyg

https://www.youtube.com/watch?v=4Dkdd287AKg

https://www.youtube.com/watch?v=3chtpC3rNh4

https://www.youtube.com/watch?v=-c8090n1Ihs

https://www.youtube.com/watch?v=6B7HrBN2tvY

When my dad had a MAF sensor code on his Buick LaSabre as well as some others, he went to the autoparts store and bought a new MAF sensor and some other stuff. The guy behind the counter said he could bring it back for a refund when it didn't fix that problem.

My dad took it back. Turns out there was some other problem with the engine (I don't remember the specifics) that caused the ECM to 'think' there was a problem with the MAF sensor. The parts guy said that he has never 'sold' a MAF sensor in all his years at the store. He said unless you physically damage it, they just never go bad.

Bad camshaft position sensors can happen and they make for some pretty ugly running because that messes with the ignition timing. I would hold off on doing anything about the P0420 until you fix the other things.

I had a persistent P0420 on my Suburban and I needlessly replaced all four of my O2 sensors ($240) and I was just about to drop $1,800 on new CATs when I discovered a crack in my exhaust manifold. The crack was allowing excess oxygen into the exhaust stream, making the downstream O2 sensor to 'think' that the catalyst was not effectively 'storing' oxygen and hence tripped the code. (Wikipedia 3-way catalyst for a proper description)

Who wudda thunk that a cracked manifold would pull air into the exhaust? After I thought about it, the initial charge of exhaust exiting the cylinder is under pressure and exhaust would leak out, but then as the charge of exhaust accelerates down the manifold, when the exhaust valve closes, the momentum of the gas pulls a partial vacuum in the manifold and sucks in clean air. That clean air resulted in a too high an oxygen reading and disrupted the catalytic efficiency calculation resulting in the P0420 code.

With the engine idling, listen under the hood for that characteristic "Thift, thift, thift" noise of a cracked exhaust manifold or leaky exhaust joint. Do not just run out and get a new CAT. You may need to check for leaks around the gasket surfaces using soapy water while the engine is still relatively cold (so it doesn't boil off causing bubbles). A good flashlight and an inspection mirror may be needed to see in all the nooks and crannies.

Good luck with your quest.

P.S. I have over 240,000 miles on the original OEM CATs and MAF sensor on my Suburban and it still passes the emissions tests here in Maryland with flying colors.

Your cracked manifold - I had something very similar recently on my old Mondeo on its MOT (annual test in UK if you didn't know). It failed on emissions and was blowing from a flange on the exhaust pipe. The guy said it was also sucking air in and causing the problem. I was as surprised as you, but I got it fixed (2 new bolts was all it took, the steel shim gasket was OK) and it then passed the emissions test.

I have one thought, uttered by Abe Lincoln, which has automotive implications also, to leave with you: "He who represents himself has a fool for a client."

Don't try to fix your own vehicle if you have to go to the local parts house for a diagnosis, and still don't know what's wrong.

I worked on my, and others, cars 30 years ago and was pretty handy. Rebuilt motors/transmissions etc. I don't even try to work on them any more.

If you insist, spend lots of time googling all the codes and how to fix them before spending any more money.

I agree with Lyn about using google to find the problem. My '04 Dakota developed a strange steering problem and an internet search for the problem showed people replacing the steering rack, tie rod ends, etc, etc. even dealers charging customers $2000 or more and the problem eventually returned. Kept reading posts until I found ones that actually "cured" the problem. Spraying WD40 on the steering "U" joints actually cured it so now about once a year I spray a little monkey piss on them and the problem has never returned! Google is your friend.

I repeat, feed the squirrels. Problem fixed! LOL

Have you tried taking it to a real shop? Autozone is not an auto repair shop. It is a parts store. Do you go to the drug store before you go to your doctor? Next time look carefully at the name on the back of the car more carefully before buying it. NOVA means "no go" and most things GM are the same ilk.