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View Full Version : 1999 legacy gt. Do I need both cats?



biocomet127
11-12-2017, 11:52 PM
So I have a 1999 legacy gt with the 2.5l engine. I installed UEL header and a one piece cat from a 2.5 rs instead of the two separate cats. After that it goes to the resonator pipe and is disconnected at the muffler Flange. The car sounds great but has absolutely no high tones. I was thinking about taking off the secondary cats to get a little more top end out of the sound but I don’t know if just the primary car is enough to let the car pass emissions. Does anyone know?

Sub-Goon
11-14-2017, 12:34 PM
Where are you at? You havent filled out your bio. It depends on your location and local requirements. Best answer would come from your local smog station.

biocomet127
11-15-2017, 07:50 AM
In on new hampisher and I’m a state inspector so it should be fine as long as the car can still pass it’s on board emissions checks but I don’t know if one cat will still pass all the checks

Sub-Goon
11-15-2017, 04:56 PM
Only 1 way to find out then!

Wiscon_Mark
11-16-2017, 09:52 AM
I had one high flow cat with an STi (OEM) exhaust system and the harsh drone was awful. I'd keep the cats as-is and work with the mufflers themselves to produce the tone you want.

biocomet127
11-17-2017, 07:24 PM
If I had a two piece car it wouldn’t be a big deal because I could unbolt it but I have the one piece so I would have to cut it and if I’m wrong that pay someone to weld it back on