Exhaust system check...

[INF3RN0666]

I've been having problems with my V6 3.3L engine. It doesn't seem as powerful as it was months ago. Lately, the Check Engine light SOMETIMES turns on (could be oxygen sensor :S) when the engine goes into high rev. I suspect that the catalytic converter is clogged because it hasn't been replaced the entire life of the engine (460000 KM). Any ideas what this could be due to and how can you test it?

My dad's impala seems to have the same problem (the 3.8L engine feels dead). Except his starts detonating at high RPM.

[NiN52445]

It could be that, but then again it could be a thousand other things. My old Cavalier suffered from a weak spark plug, and my parents Sebring had it's fuel filter clogged. Both those problems lead to decreased performance. I'm no expert, but that sounds like a problem you'd need a real mechanic to look at personally.

[jimmy[the]gent]

i have never heard of a catylitic converter clogging when they wear out dont they just stop working and make the exhaust fumes delightfuly deadly

[INF3RN0666]

well I know that there's a loose part in my catalytic converter. When I press the gas peddle and get the RPM above 2000, and then release the gas peddle, I hear a repeated metal "CLONK" coming from the catalytic converter.

BTW, why wouldn't a catalytic converter clog up? It's basically like a honeycomb. Any debry would collect on it and clog it up.

The wierd thing is, my car that has 460000 KM on it and has never had the catalytic converter changed outputed AMAZING results when it was E-Tested. However, my mom's cavalier that only has 130000 KM on it outputed decent results when it was E-Tested. That only leads me to believe that not enough exhaust was coming out of my car :P. As much as I love the Earth, I'd rather a car that outputs deadly gases and runs well than a car that chokes on its own breath and saves the eath!

[Oldengineer]

GM's got a problem with converters plugging up on some vehicles. A friend of mine at work had the one on his 2003 Impala plug so badly that the car wasn't driveable. It took the dealer a month to get his car fixed because the converters were on national backorder through GM. Suggest you have your dealer check it out for you.

Regards:
Oldengineer