Pre Cats
 

Are they necessary to pass DEQ? The 5 spd crossmembers are basically sitting on the pre cats, so I have to act soon. I am planning on cutting the front pipes just downstream of the o2 sensor ports and removing the two cats and putting in a straight 2" pipe on both sides. That would certainly solve my clearance problems. And I would be retaining my center cat, or at least a high flow version of it. What's are the pros and cons of this? Other than legality of course. Thanks.

Stephen

Most replacement (non OE) cats replace both pre- and main cats in a system. Check with your supplier regarding the specific model you plan on using.

Actually, I am going to use a universal hi-flo dual 2" in and single 2.5" out for the center cat. And straight pipes up to the headers.