Just finished the rebuild on my 94 Z M6 but still havin issues! Wondering what the symptoms would be of a bad opti? fuel pressure is at 58 psi even when the car is cutting out and eventually stalls. it has a rough idle and while reving it up the car cuts out like there is no power.

 

Probably the same symptoms that you would have if the car is not tuned after doing all that work. If you have it tuned properly, then it would backfire, miss, idle rough, and many more symptoms. How many miles on the origional opti, if you did all that work I would have just gone ahead and done the opti while it was off. If you do that may as well get a remanned water pump and new thermo as well, because you run the risk of the waterpump leaking at the gasket once its taken off and thanks to GM that will ruin a new opti. Plus they are cheap, remanned ones are like $50.

 

Probably not a good idea to start another thread when there is already one regarding this problem, with a lot more into in it.....

http://camaross.com/forums/showthread.php?t=544581