Ok. This confirms what I thought. There is a tuner that you can buy that will allow you to change the ignition tables and such. It's called the syked tuner or some such. Might be worth it especially with other mods. I don't think my plenum is leaking as there's no oil puddling on the plate when I look down the throttle body. Id like to improve the exhaust system and have a suspicion that one or more of the cats is clogged. The front left car does rattle already.