I got a 2003 Tahoe with a 5.3L flex fuel. I just replaced the intake manifold gasket, MAF sensor and I put new a set of E3 spark plugs in with a set of wires. I am not to happy with the E3's as of it.

I am looking into getting some Pulstar Pulse Iridium spark plugs here pretty quick. Has anyone used them yet or have any imput on them? Then what brand of plug wires should I get with them or does it really matter?

Then on top of all that I just put on a Spectre cold air intake. Which seems to give my gas pedal a little more power to it.

 

Recommend you stick w/ AC Delco based upon what others have experienced w/ non-OEM plugs. Once your ECM learns the new air flow characteristics of the the CAI, things will return to normal, if they really ever left it. Check out a Blackbear tune if you want lasting real results.