awcjacobs

Just had a ATF service and for the last 6 months I had a rattle underneath, had the Tech take a look. He said the upper cat is to blame and needs replacing, an estimate of $1400.00 for one, but he said the best option is to look into down pipes which would cost the same for two. Unsure if putting on aftermarket downpipes would pass air care? You guys in the lower mainland have any hints or answers?

mikeh

The pre-cats are there to capture the nasty stuff when you first start the car up. After the car is warm they don't do much.

Get rid of the Pre-cats as many of us have. It shouldn't effect the drive clean or air care? You will also have an increase in power gain.

awcjacobs

Thanks Mike

Sounds like a win - win situation. Any recommendations on manufacture?

K04-S4

VAST 2.7T "Piggie Pipes" are good or if your inclined then you can do the same mod yourself on your existing downpipes. Modding your existing pipes would cost $80 or less depending if you can weld in the replacement bungs yourself in order to relocate the rear O2's to behind the main cats for no CEL.

awcjacobs

Unfortunately, do not have the gear nor space to weld or do work. Going to give the guys at VAST a call, like what they have to offer.

awcjacobs

Thought I would update on what I did with regards to exhaust. Met a performance mechanic at a drag race and chatted with him for a bit and told him about the 2.7 I have, the downpipes and that I would need new exhaust. Anyway, he refurbished the downpipes as he knew about how VAST did there's and we put a magnaflow system on. Sounds nice, bit more pep.