Headers or cat delete pipes?

[jaykay]

If you go by the old Fabspeed web site....the 2nd cat deletes show more hp gain. This is with catted headers I believe. It has been noted on this forum that going with catless headers (even cheap ones) and monitoring catted mid pipes provide the best performance....provided you have the diameters correct and are not upsetting scavenge velocity. There have been issues with extending O2 leads to the mid pipes and warm up codes noted as well. This can be cured with a ROW flash.

Then we come to the muffler. Apparently it flows quite well and is good for power, although it is heavy. I have mine bypassed so it is quite nice sounding.