I have an OBS (2000) Chevy 3500 with the 454/4l80E. Currently I'm running 2 flowmaster 2 chamber mufflers (40 series I think) dumped above the axle. I'm contemplating removing the catalyic converters. I'm not concerned about emissions, but I am worried about losing low end torque due to the change in backpressure. I was wondering if this is true or not. The other part of this question, is what affect will this have with my PCM? As far as I can see there are no 02 sensors of any kind behind the cats. only the one behind each manifold.


I'm also trying to find some good headers for it, and was looking for some suggestions as to who might make a header for this application.

Any help/advice would be greatly appreciated.