I have a stock 88 iroc 350, auto trans. when i get on the gas i have a rattle noise that seems to be getting louder. i heard it could be my cat but im not sure any ideas? it almost feels like i have a lose in power too.

 

I don't get the loss of power, but I would check all your exhaust clamps.

 

check your timing, it almost sounds like spark knock and the computer is backing off the timing to compensate, hence the loss in power.

others may want to jump in here though.

 

Sounds like he is talking about a severe case of pinging. If that is what you mean then you need to troubleshoot the cause. It could be carbon on the pistons, timing, an extremely lean fuel mixture. Let us know some more details.

 

thans guys ill be checkin the car out tomorrow for these problems and get back to u with what i find. thanks again.