I have an exhaust leak on my drivers side collector flange that is quite bad and makes a really loud hiss noise at WOT. It also feels a bit rough at WOT and power feels like my car has stock manifolds again (I have lngtubes now), could all these things be caused by the leak or does it sound like more than just the leak giving me trouble?

 

it will have alot to do with that leak. It could also be your o2 sensors as well. But get that leak fixed first and then see how it works. it should clear it up.

 

check you header/head head gasket at the flange. this usually creates a ticking more than a hiss, but what the hell. also had leaks before the cat before

 

Mine is OBD 1 so no O2's after the cats and the leak is directly after, maybe 5", the o2 sensor. I also just replaced the opti but dont see why that would act up only at WOT. I might have to di a datalog with datamaster and if I cant decipher any problem have someone else maybe on the board take a look. It does have a slightly more bumpy idle might be the coil Im using since its not the same one as before the opti replacement. I dont remember what started the leak I mean a few days after we took the exhaust off and put it back on for the LCA's and rear spring swap it started doing it. Looks like the exhaust flange doesnt meet up with teh header flange at teh bottom but everything is TIGHT. Ill just have the exhaust shop look at it once I need the cats replaced.

 

Just a long shot, but you might check your wires if you haven't already. That may cause problems as well.

 

Guess what guys, I was listening to it against a curb in 2nd gear at about 35-40 mph laying into the throttle and backing off just listening and wondering. It sounded like a whine like a supercharger almost, it was almost exactly like a gear whine and VERY loud probably soudned like a screw type charger was on the car but it only had 250 fwhp, lol. It was almost cool if it werent for the slowness and slight roughness at WOT, but after I layed into it 5 or 6 times and let off I heard almost like a crash or ping within the exhaust. After that the note immediately got louder and deeper and all power was restored... it must have been a large piece of the broken apart cat that lodged itself sideways in there and the whine was I guess all the air rushing past it VERY quickly and the roughness from the tremendous backpressure on 1 side of the motor only. I still have the leak which I plan on fixing but it drives just fine once again PHEEEEW I wonder if anything was ejected from the tailpipe lol.