danbrazda

Previous owner installed my cats so I don't know how long they've been on the car- When I swap out my Cats for straight pipes there is no difference in sound, both volume and tone. Shouldn't there be a noticeable difference? Are the Cats shot?

ssteven

iTrader: (6)

Id say yes. I replaced my cats at 100K with magnaflow direct fits. the car runs better, louder and milage increased.

RPM WS6

iTrader: (3)

Have you looked down the pipe to see if the cat material is still present? Someone may have hollowed them out. If there is zero volume/tone difference, then this would suggest that the cat material has been removed. The exhaust should be louder and more raspy without the cats. The difference won't be quite as drastic with smaller high flow cats, but it should still be enough to notice.

It's not something I would worry about unless you have to pass a sniffer test. The car will make best power and best MPG with off-road pipes.

danbrazda

I've looked inside and there is definitely material in there but I'm not exactly sure what it should look like. They came with the FLP Long Tube headers. Car is VERY loud, which I don't mind but I'd like the option to quiet it down a bit when I want to. Resonaters? Different kind of HiFlos? Car is lowered so I need something low profile.

NC98Z

iTrader: (1)

The smell of unburnt gas is the dead give away. Catted cars with long tubes, heads and cam can be very loud.

homerz28

Do cars with high flow cats still stink like no cats?