[Sumdude]

OK this is whats happening. I have this 02 impala. And if you have the slightest knowledge of these cars they are known to have power. Now my car is not the case. When im at the light and the light changes everyone is way ahead of me and i can fell like my car is trying really hard to build p speed. Its not transmission problem cause it shifts PERFECTLY.when i reach 25 and then at 50 then so on. Now according to most reviews of the car it should be getting about 23-26 in city and about 32 on highway. Here again its not so with this car. I get about 15 at the most without ac on. I've put a fuel injector cleaner in and i dont even know if it helped. Do you think that it could be a clogged catylic convertor, spark plugs, fuel filter. Please just looking for a solution. P.S. ran computer scaner and no codes came up.

 

[ganzhimself]

You have a clogged cat. Have your exhaust system's back pressure tested. VERY common problem on 00+ Impalas. Your car *might* still be under warranty on the catalytic converter, so a dealership would be able to replace it for free. I believe GM extended the warranty to 8 years or 120,000 miles. If your cat is clogged and you're looking for a little bit of an upgrade, I'd suggest getting a 2.5"downpipe from ZZP with a high-flow cat. The ZZP downpipe is less restrictive than the stock exhaust downpipe, and has a catalytic converter that is of much better quality than OEM. You'll want the 2.5" with cat: http://www.zzperformance.com/grand_prix/products1.php?id=551&catid=110

If you're looking for the best Impala community online, check out http://www.naioa.com. We can help with just about any problem you'd ever encounter with your 00+ Impala.

 

[pfc]

Its The Transmision

 

[liqsteal]

lol stop buying cheap gas and go to the next highest octane i only put mobile in my chevys and even my beeter gets 89 or higher octaine oh yeah change the oil and air filter that helps alot