I don't know exactly which way to go with this, but it seems as if after I had my exhaust fully welded into place instead of just bolted on I have noticed a major change in power. It's quite possible that this has come from something other than welding, and I just noticed it more after the welding was completed. The car is not nearly as loud as it was before (possibly due to the fact that my Y-pipe and intermediate pipe were inserted into one another only).

But here is my main problem that makes me ? a major powerloss, raced a C5 Vette and walked away from him 70-110 and had 2 cars on him, raced 2 stock LS1 Camaros automatics and beat both by over 2 bus lengths 0-120mph, then just the other night raced and LS1 Camaro 6-speed with the muffler cut off only (inspected the engine and everything for any bs on why he stayed right with me) and I couldn't do anything but start to pull on him after 80 mph. And no it is not my driving ability cuz he stayed beside me at a 60 punch in 3'rd gear.

I have put 1500 miles on my engine (see sig) and the only codes that come up are EGR Valve and the rear O2 sensors not reporting. I have a custom PCM tune that disabled the rear O2's and my EGR system is not hooked up. My ses light will flash off and on every now and then, and it seems to happen after I keep the rpms around 3000 in 2nd-4th (if I just hold the gear) it doesn't happen in 5th. I have a CC306 cam with roller rockers and my idle is a little high at 1100 rpms, the rr seem clack but not overpowering as people on this board seem to have with them. Can the fact I should retighten them down make me lose that much power?

I am just at a loss, my mechanic that I had do the install didn't tell me $hit or show me how to do anything, so I am getting my new mechanic ( he built race engines for 6 years) to look at her tomorrow, but I am just confused, I have a 430hp engine and it just doesn't feel like it recently has that much power. Pardon my ignorance but I am trying to educate myself as best I can. I wish I could provide more information, so let me know what else I need to answer. Thanks.