November 20, 200916 yr 88 XT6 manual AWD is only getting about 15mpg. i should get 20-25 with the kind of driving i'm doing and close to 30 highway. Is there a good way to track this down? not looking for a laundry list of possible things, i realize it could be dozens. I'm thinking there's probably only one or two things that can make it this bad. Runs perfect, no check engine lights, PCV, plug wires, cap, rotor, plugs all replaced. Brakes all redone and crisp, bearings tight. I have a new O2 sensor but haven't installed it yet - an O2 sensor wouldn't drop it that much, would it? I've run without O2 sensors and it didn't seem that bad, but its been awhile. Fuel pressure regulator? i'll have to look up how to test those, or if it's easy i'll just swap one in?
November 20, 200916 yr Author My vote is for the 02 sensor.sweet, i hope it is. anyone have experience with an O2 sensor making that much difference? i've never had that happen. How is the engine power wise?seems fine.
November 20, 200916 yr I had a non-Subaru car's gas millage go south on me one time... Car ran good, but had a "hot" starting problem sometimes... It ended up being the coolant temp sensor had went bad, and the ECU thought the motor was cold so it had the fuel enrichment (choke function) cranked up all the time, I changed the sensor and the mileage came back. That car used two different temp sensors one for the gauge, and one for the ECU, temp gauge always looked good. Might be something to consider, and not trying to be a jerk here, but have you checked for under car fuel leaks? IASUBE
November 20, 200916 yr Author i wanted to install a new coolant temp sensor connector anyway since that's a common issue on the XT6 and i already have the connectors, so i'll do that and clean the sensor or maybe even replace it.
November 20, 200916 yr Yeah - I don't think the O2 would drop it that much either. I have seen them bad enough that the engine wouldn't run but that was with a feedback carb EA81. Probably just a fluke with that primitive ECU..... The CTS is a good sugestion.... perhaps the CTS is reporting cold and the O2 is reporting lean as well. Leaking injectors? GD
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now