i've posted which headers and exhaust to go with and got back that the headers will make me run lean, if i get the cats or test pipes will this do the same? if it is a good thing to go with which one should i go with? also, if you run the the high flow cats or test pipes, does you check engine light come on?

 

You will run leaner with headers, but the Vortech kit out of the box is plenty rich to accomodate them (along with cats or test pipes). However, if you have your SS box custom tuned beforehand you'll obviously need to tune again so my advice would be to install those things first and tune once.

--Steve