Does changing the throttle body and spacer really add that much HP? Mine 4.0L. My neighbor has a 2008 & he said it made a significant change. He also added a cold air intake.
I've got a 1998 TJ, OBD code P0301 showed up yesterday - cylinder 1 misfire detected. Any idea as to root cause(s) as to what the heck is the issue i.e. plugs, O2 sensor, egr valve, etc?