What are the signs of a bad opti? Have a crank sensor "circuit" code and car runs crappy. Any ideas?

 

More details are needed. Like what year car, what exact codes, etc. Crank position sensor codes don't have any effect on performance. The sensor only monitors for misfires on an LT1.

 

It is a 97. It runs poorly. exhaust manifolds are white looking. It doesn't have a dead miss just no power. 335 and 336 codes.

 

As stated, the CKP has no effect on performance. Although the circuit does have what appears to be a wiring problem and should be dealt with. Since your manifolds are "white" is it possible your cats are clogged causing the manifolds to get hot and your performance issues? Just unbolt them and give it try (with earplugs).

 

I unbolted manifolds. still runs poorly. Fuel pressure up in the 40's with line off of regulator. Higher rpm it runs just "fair" lower rpm it is horrible. no throttle responce.