Cut out of the OE muffler (dual inlet/outlet 3? on 2500 HD) and replaced it with dual glass packs yesterday and ran like a scalded cat. Was doing a pull on the highway and hit ~100 at WOT in 3rd and 6000 RPM and bounced off the rev limiter (I guess, have it set to 6100) and now the truck feels poochy. Doesn?t pull as hard in 1st 2nd and 3rd at WOT, hits power enrichment just like it should (11.9-12.3 AFR), but feels like it?s pulling a heavy trailer. Did a log run to see if there was knock and everything was coming out clean.
Didn?t retune after muffler delete yet, but I can?t imagine that it threw my tables off that much that the ECU couldn?t compensate? Hasn?t thrown any codes. The only tuning I have done on the transmission is adjusting the shift points. No torque adjustments, etc. I have the 2006 Silverado SS shift table in it and the WOT MPH shift from third is set to 255 Mph so that?s what held it. Also my AEM gauge goes blank when I let out after a WOT pull until I tap the gas and then it comes right back to the 14s, could just be a malfunction? Or maybe something weird with the pulses due to the velocity at WOT and then me letting out?
Engine is a 6.0 with 706 heads, 10.5 compression and Truck Norris cam and bigger injectors.