okay found out that an a\f guage can fu#$ your engine up by messing with the voltage your O2 sensor sends to the ecu. So would it be better to install a second O2 sensor, so you don't mess with the voltage that is sent to the ecu, or is there some other way to guage if the engine is runing rich or lean??? Egt guage maybe???

A/F are not good measurements of how your engine is running. The regular four wire O2 sensors cannot read wot conditions very well. The only O2 sensor I would trust would be a wide band (but they're VERY expensive). Secondly EGT's are a pretty good way of monitoring you're motor. I would personally go with an EGT.

what is an EGT??

EGT= exhaust gas temp.

EGT is Exhuast Gas Tempature, how do you tell how the engine is running with something like this?? what are normal operating ranges?? and how hard is it to install, it goes on the manifold, near #1 cylinder right?? what is the better brand to get?? auto meter ??

thanks guys!:)