K.T., here in Rutherford county, Tn. they use the OBD 2 connector for emissions testing to see if any codes are set. My Hot Cammed, Corsa exhausted (hehehe) LT4 has no problems going through the testing. No codes. I do get the occasional SES (service engine soon) light because of low idle mis fire every now and then. Of course the light goes out after several miles down the road.
However, I picked up only 15 or so HP on the dyno. The hot cam needs to have headers (long tubes) to make it work properly. I do run hotter now, about 10 degrees more while cruising. If you are not going to go with headers and a more open exhaust such as hi flow cats and something like corsa at the back, then it is really not worth it.
I currently have my headers hooked up and now must fabricate the hi flow cats to my corsas.
The TPIS headers are a POS. I had to grind on every aspect, holes, flange, tubes to get them to work. Don't get TPIS! Check out Exotic Muscle. They now have a bolt up kit that is supposed to be much better.
