Mid-Pipe or Cat Back first
 

So I have the stock stainless steel exhaust on my 2004 GT with some flowmaster 40's and a ton of mods under the hood. I ready for exhaust now, should I do an X pipe with high lows cats or a Magna Flow or Loudmouth II cat back exhaust.

Remember I need to stay smog legal as I live in the tree hugger state of California.

Thanks all Matt

This sounds like a job for Mr. r3dn3ck

Leave the mid pipe alone since it's technically illegal to go from a 4 cat to a 2 cat set-up.

Actually it is illegal to remove any working emissions equipment on a vehicle with less than 50k miles on it. Once you pass the 50k mark, you should be able to legally change out the midpipe for another with high-flow cats, provided you still pass the smog check.

Yea I only got 20k on the car now in 4 years so I won't be hitting 50k for sometime now. Thank for all the input...!!

Matt

That too but according to Car Sound's site (Magnaflow cats), it is also illegal to consolidate the emissions system.

I ran a mac prochamber with cats on my mach and I live in Cali....I think it would pass the sniffer, but Cali does a visual inspection as well. If they see only 2 cats then you get screwed.

here is what you do. Get whatever mid pipe you want, keep your stock one and when it's time for smog or you get caught by the cops just put your stocker back on....That's what I did.

DIDO!!!