Hi I have a 2000 jeep Cherokee 4.0 with an automatic transmission and 140,000 miles. Current gas mileage is 7-9 mpg in town and 10-14 mpg on the highway. I have replaced spark plugs, ignition coil pack, cam and crank sensors, and recently changed the oil. The short term fuel trim is 18-20, and short term fuel trim is spot on 0.0. There are codes for the battery voltage sensor and neutral safety switch. The vehicle drives satisfactory. Any ideas? Thanks for your response.
How old are the O2 sensors? (If it has CA emissions there are 4 of them.) How about air filter? MAP sensor OK? Fuel injectors?
Bear in mind that normal gas mileage on these is about 15 mpg, give or take a little.
The vehicle drives satisfactory.
the 8 mpg and 19% LTFT would indicate otherwise.
Start with the voltage problem. Get your charging system (battery + alternator) load tested.
