The muffler fell off my work truck. I picked up a universal glasspack for a cheap fix. Clamped muffler on took it for a ride and it stalls when coming to a stop and feels doggy when accelerating. Pulled over unbolted the muffler and all issues immedietly stopped. Cant figure it out any tips would be appreciated. Specs on truck- 94 chevy 1500, 4.3v6,

 

Is it the correct size? Glass packs are a pretty free flowing design.

 

Yea its the correct size. I thought it could have been a clogged cat but my uncle that was the previous owner said he hollowed the cat out.

 

That sure is strange your truck runs bad with a glass pack but runs normal with an open exhaust. You are saying you took the glass pack off (open exhaust) and the truck ran normal correct?

 

Yea open exhaust it runs great, as soon as i clamp on the muffler and take it down the road it runs like crap. Even tried running it backwards in case the inlet/outlet was mis labled with no luck. Ive never seen a problem like this. Im about to just get a section of straight pipe so it exits further towards the rear so its not as loud in the cab and call it a day