Ok i have a '86 T/A with a 350 TPI w/ the mods in the sig. My question is, would i be better off with a high flow cat or a hollowed out one? Right now i have a high flow. If i hollow it out what would the difference be?

Thanks in advance.

 

either don't touch it or put a straight pipe through it

 

I wouldn't touch it, if you have a high-flow cat that is working properly the improvement will most likely be minimal.

I run no cat and I noticed a big improvement because my original cat was old and partially blocked, however, even though the car passes British emission tests it does smell now and it didn’t before... Ideally I’d have a high flow cat.

 

Well i have to have a catalytic converter so i cant just remove it and run straight pipes. I heard if you hollow out the converter that it will make your car a little louder? I wouldn't mind my car being a bit louder but not too loud.