I installed the MRT up-pipe and the turbo-back exhaust a couple of weeks ago and I finally got the dreaded CEL on Sunday. It was very hot and I was testing my car down a curvy mountain road. I assumed it was the cat inefficiency code because beside the BOV and suspension, I don't have any other mods. The light went away this afternoon. I never got a chance to pull the code at Autozone. Has this happened to anyone else? Should I still invest $20 for a voltage clamp?