Just recently fixed the plenum pan leak, changed plugs, rotor, cap, timing chain, water pump, T-stat, and new gaskets. Milage was around 10-13 city, 15-17 hwy. Now city milage is 13-15, but have not had a hwy trip yet. After repairs I went back to stock programing from Hypertech. Milage and power are both up with no pinging. I just use the Hypertech now as a code reader and tire size adjuster. Jeff.