i changed valve seals on my brothers 91 chevy pick-up 350 engine.then we found that the pcv was stopped up.i cleaned the front of the thottle body and sprayed some BRAKE CLEANER into the nipple on the bottom of the thottle body. now that thing SMOKES white smoke and has the awfulest toxic smell you have ever smelled.what have i done ,is there some type of chemical reaction going on with the converter???we drove it about 25 miles and still the same thing.anyone ever ran into this or got any ideas.i hate to get off the camaro scene but thought some of you guys might know. thanks!!!!!!!!