for you guys that are cat-less up/dp/mp, how do u pass inspections? do you revert back to stock when u get inspected?

for those that keep one cat, which do you keep? how should i decide which part to keep the cat in?

im under the assumption right now that most aftermarket DPs are basically DP+MP in one piece, or am i incorrect? (learning as i go).

im planning on mixing and matching a HKS hi flow catback with possibly a perrin DP, but do i get the cat or no? im so confused right now lol.


also, i was looking at gruppe-s.com...they sell alot of stuff for VERY cheap. anyone have any problems with them? everything ive read about them is only praise...i was wondering about their in house items, like their uppipe, and exactly how they can be so cheap.

any help appreciated, thank you in advance.

 

Removing any cats is illegal, but since most inspection stations have people who don't know their asses from their elbows, they won't know the difference between different up-pipes and down-pipes. If you're only going to keep one, keep the one after the down-pipe. I don't know if that alone will pass your state inspections, but it's the beefiest, and I would think it would be okay anywhere except California. Most WRX owners have yet to need an emissions inspection, so I haven't seen any reports on people failing yet. You may also fail inspection for an exhaust that's too loud, but that'll depend on your state laws and the inspection station. I'd definitely keep all your old parts on-hand, but you'd probably have to worry more about the loud exhaust than the missing cats. Just some things to think about.

 

Has anyone ever been to a Inpsection station that had a AWD dyno? I dont know about other states but in Jersey thats how they inspect emmisions. They check it at idle and then at a certain mph/rpm. My car came with a little piece of paper that basically says to warn the dmv that this car is AWD

 

Last time I was tested was in my 96 talon tsi awd. Sense the emmision place did not have a awd testing unit, they just put the sniffer in the exhaust and tested my car at idle and at 2500rpms. I had a 3inch exhaust system on the car with an after market cat and pasted fine. I cant rember the numbers exactly but I barely even registered on the sniffer. Helps when the old turbo doesnt spool

 

thanks guys, ive decided on going completely catless, never really dawned on me that i could just swap out the catless dp for the stock dp/mp with cats

 

the most invaluable resource i have found yet is by far i-club