I read in my search results somebody who said by eliminating the first cat on each side they measured the exhaust backpressure drop from 10 to 7 psi. I also read on another thread that the second cat is the least restrictive. I was wondering if these two statements might have any truth. I was thinking of getting rid of the first cat and just running the secondaries as opposed to getting high flows since many people seems to have trouble with them. Not saying that the stock cats won't come apart pushing 450 horsepower just thought i would give it a shot before i take em off and run straight pipes. By the way isn't there a preesure port where you can measure the backpressure in our exhaust. If so where is it and what tool do i need to measure it. Thanks.

 

The Magnaflow low restriction cats don't seem to have the same problem with coming apart. They do have the ports for all four O-2 sensors, and much less converter area, so they will require ECU reprogramming to work properly. Now comes the real question. How well do they work? If you can hang tight for a couple weeks, I'll post the answer to that question. I'm going to baseline a truck on the dyno, and then install the Magnaflows and run it again with no other changes. Everyone seems to agree that the factory system is pretty darn good, but I don't think anyone has posted the results of doing just the cat swap. I will do it.