Well...my cat is making this really funny noise when i step on the gas. It sounds like I have an exhaust leak but I checked all over and I don't. I think all the baffeling inside the cat is all messed up and rattling around. My power has decreased also. I called chevy and a stock cat cost over 400 dollars. Does anyone know where i can get a direct fit high flow cat..or a decent universal one that fits....also...does anyone know if the stock cat is under warranty

 

it should be covered under warranty if it is causng problems

 

Magnaflow Catalytic Converters are barely over $100. Just get one without a O2 sensor bung and get the same diameter as your stock catalytic converters inlet/outlet.

It sounds like your catalytic converter is clogged.

 

A catless DP is cheaper. And 400 for the stock cat? I'm calling BS.

 

Stock DP from GM is going to be pretty expensive, anything through GM is going to be expensive. Just replace the DP with an aftermarket one with a high flow cat. Won't cost you more then 250 for the whole DP w/high flow cat.

 

Your catalytic converter is covered under warranty. Even if you are going with an after market dp go get the new one from the dealer anyway.

 

i believe its covered for 80k miles, i just had mine replaced by chevy service out in cali.

 

is it like a whistling sound in your exhaust? Have you seen higher boost levels, but shitty performance? I'm sure chevy service would replace it anyways if you haven't done any modifications. After i modified my cat to 3" piping it seems to put much more whistle into my exhaust almost like i have a turbo, i have a pretty shitty resonator though.

 

your dealer has to warranty it. emissions law

 

Yeah dude they are REALLY expensive new. Here's what's in them:

"The catalyst itself is most often a precious metal. Platinum is the most active catalyst and is widely used. However, it is not suitable for all applications because of unwanted additional reactions and/or cost. Palladium and rhodium are two other precious metals that are used. Platinum and rhodium are used as a reduction catalyst, while platinum and palladium are used as an oxidization catalyst. Cerium, iron, manganese and nickel are also used, though each has its own limitations. Nickel is not legal for use in the European Union (due to reaction with carbon monoxide). While copper can be used, its use is illegal in North America due to the formation of dioxin." -Wikipedia

 

DAMN I would never replace mine with the stock peice but geez, thats crazy money for a stock DP.

I have a whistling sound, Its really annoying but I don't think it effects the performance too much. It almost reminds me of the sound of knock.

 

^^^ Yeah that's why you keep your stock one

 

Cats ARE covered for 80k miles!

 

Its a weird sound..not really whistling. it almost sounds like i have an exhaust leak but I checked everywhere and I dont. I made an appointment to go in monday to get it fixed. My car is really bogging down too...kinda sucks.