i have a 94 grand prix and just changed a timing belt on it.it's the 3.4 dohc engine.problem now is it ran fine for about 10 minutes then upon it in idling, i gave it some gas by way of pulling on the throttle under the hood and there appeared to be a loud hiss from the front of engine then and engine started to idle roughly,the cat also is making a lot of noise, like it's all broken up inside,it wasn't this bad before belt went.but i had test run the car several times adjusting timing belt aand it ran several times with cams out of time,if the cat was going bad to begin with,could the engine out of time running really destroyed it????just what are the signs of a bad cat????what was the hiss then rough idle????is the cat bolted up to where i can replacwe myself???
- posted
17 years ago