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.

 

I removed the 1st cat (Uppipe) and the 2nd cat (downpipe) and left the 3rd cat for visual inspection @ DMV. I purchased a Bosal DP that connects from the turbo to the stock 3rd cat eliminating the 2nd cat. I purchased a catless uppipe and that took car of the 1st cat. From my research the two most restrictive cats are the first and third but I didnt want to eliminate the 3rd cat because of the DMV inspections.