Ok, I've heard the stock cats can gunk up pretty bad and be a real chokehold on power. Question is, how do you know when they've gone bad? Noises, mileage, no way of telling?
If I were to replace my cats could I pass an emmisions test with highflows or could I just buy new ford ones and only use 2 instead of the 4 stock cats and still pass?
Also, how much do you guys think a muffler shop would charge to convert my fake duals to real duals. I have mac's truefit duals and I want the muffler shop to just cut my y pipe, weld in new cats, and make an H pipe for me.
Here's another one of my crappy drawings.
The one one the right isd what I'm talking about. Color coded for your reading ease!!! :p If it makes a difference everything connects with ball/sockets, now welding or cutting was done to my exhaust.