I just got the car this weekend, 1995 v6 5m. Monday after work, the car was having a real hard time starting, kept cranking without even trying to start. Got it started and it ran fine out of town. Started down a long hill from a stop, hit third gear, and it suddenly bogged out, then stalled. I didn't realize it stalled at first (radio loud). I hit the throttle and heard a loud hiss, somewhere between a vacuum leak and turbo spool. Coasted to a stop, and it wouldn't start again. Let it sit for 10 or so, and it started right up. Drove it 2 more miles and it stalled out the same way, going down another hill. Got it into the driveway, and it was running real rough. Shut it down, let it cool down, and started it up 1/2 hr later. Started right up and ran almost smooth. Took it down the road, noticed that hissing every time I got past half throttle. Stalled out a few miles out, I jumped out and walked around the passenger side, where there was a lot of heat coming off the cat. Got it back and parked it. It also seems powerless, and when the throttle is jabbed, there is a brief bog before it revs. It runs very rich, though I don't think it ever gets into closed loop because my fan is on a switch. I cut the cat out to look at it, and its a bit discolored from soot, but not clogged. I've got it out still, I don't want to put it back until I'm sure its not exhaust related. I'm thinking it might be spark related, or possibly timing, but I'm unsure how to proceed from here. There is no check engine light either. Sorry for the wall of text. If anyone can point me in a direction, id appreciate it.

 

i would have thought it was the cat being plugged. so does it run any better without the cat? have it scanned for trouble codes.

 

Problem isn't any better with the cat out. I don't have a scan tool myself, and the nearest auto zone is farther away than the car will go. I'm wondering if it might be an egr valve... also, once upon a time I'm told cars had valves in the exhaust manifold to help them warm up faster... don't remember the name of it. Any chance my car would have one of these thats sticking? My old man suggested possible vapor lock, but I don't think it would smell so rich if that were the case. It definitely seems to me that its something thermally controlled causing the issue, otherwise it wouldnt need to cool down, correct me if I'm wrong. Right, off to apologize to my neighbors for the open pipes...

 

unhook the egr and see if things change. im still trying to figure out this hissing. can you get a recording of it? with the cat back on. lol.

 

^ But his cat isn't doing the hissing.
Any chance you may have bottomed out and flattened an exhaust pipe?
Or....did a "buddy" of yours play a prank and jam something up your (car's) tailpipe? heh heh
I can't think of what else could be hissing either. Your story sounded like a restricted exhaust, right up to the part where you said you removed the cat.

 

Remember guys, always jack on a solid level surface. I almost just got ended because my drive isn't one or the other. Where's a good spot to put the stands when trying to unbolt the exhaust? See if I can't get it right tomorrow. Then hopefully see about the egr and a recording of the hiss.
I was also told these v6 have a tendency for faulty ignition controllers. Will see about that too.