so i took my y pipe off today.. i have slp lts,y with cats and a flowmaster exhaust.. ne way i took off my y and i discovered that i cat has nothing in it?.?.? so i made a decision and gutted the other one.. question is.. should i put some pipes through them or just leave em alone.. i wanna leave the gutted cats on in case there is any kinda visual inspection.. ive been running this setup for 3 years and have had the y off before and i never noticed there was nothing in one.. weird..

 

leave em.....

 

My question is, did you buy it new, used or on the car already?

 

i bought it used from somebody but it had had like 5000 miles on the whole setup..i wanna say when i bought it i looked and the cats were good.. i must have blown one out.. i did hear some rattling in my exhaust a while ago then it was gone

 

same here, i heard some pinging noises and found one of my cats blew out so i was wondering if i should shove a pipe through the cat or just leave it alone empty. I have heard from some people it restricts flow and other say that the flow of air rattles through the hollow can of the cat and makes it raspy.... any thoughts?????

 

i just left the shells.. i think it sounds good, no raspiness

 

what about loss of power or torque???

 

i dont feel any.. car runs nice and strong

 

I've experienced this before. The hollow cat reduces rasp. When I completely removed the cat, there was a volume increase, and a big increase in rasp.

As far as flow, a straight pipe will flow better than a hollow cat. The empty chamber messes with back pressure and airflow. It won't kill you..but it will effect it some (maybe 1 or 2 hp)

Cliffnotes: Hollow cat = little - no rasp
No cat = rasp.

 

I dont think they blew out on their own, they have a ceramic honeycone inside, that had to be beat out with a hammer and a chisel when I removed the guts of my cat. very tough to get out.

 

I hollowed mine out. I picked up 1.5mph in the 1/4

 

that is some crazy ****. My car came from florida, and it had the same thing. Catted Y with one gutted cat. i went ahead and cut the cats out and mig welded in some 3" aluminized tubing to pick up some ground clearance. It made a believer out of me though, as it has a flowmaster true merge (2-3" into one 4") because it has ZERO rasp at any rpm. even a high rpm decel. also have an E cutout