Originally Posted by carta79
What's the mileage?
Cap & Rotor , Fuel filter, PCV valve, Oil change.
Reset your ECU due to fact that you swapped it out. It's possible that the ECU remembers when the car ran rich.
I replaced the fuel filter about 4 months ago, I do oil changes every 3500 miles, and I've properly reset the ECU. While I haven't done cap and rotor or pcv valve, I don't see how these could account for such a drastic reduction in fuel economy. I usually get about 250ish miles by the time it is on E. Divide this number by what usually is around 11 gallons and you get like 23 mpg. Could a bad thermostat account for such a big drop? I am pretty sure my thermostat isn't working all that well since it usually takes a long time to get past C when it is cool out and the temp gauge will drop back down to nearly C if I am on the highway....Any other ideas?
Oh yeah, could getting a VAFC and tuning it help? I mean, since you can optimize a/f and whatnot. My buddy suggested at least hooking up an air fuel meter to see how it's really running...