Opti problem?

[Madman337]

I have had this going on now for some time and it seemed to start after having a car wash spray my opti (I didnt know not to at the time) but I can watch the tach needle jump up and down kinda like a surge but I also swear I feel the converter locking and unlocking too.
Has anybody else had this happen before and also what are the symptoms of imminent opti death?

[cholmes729]

my tach jumped when my opti went bad, it slowly got worse to the point it would backfire out of the exhaust, then it would start dieing driving down the road. Pulled the opti off, and the bearings felt like they were full of dirt. Put a good stock one on and its been good since.