I have a 2001 Subaru Outback 2.5 Limited Sedan. The Check Engine light is intermittently going off and on. I think this may have to do with a fuel line problem. I recently moved to a new place and started buying Unleaded Gas from the nearest Gas Station. The Subaru started to have problems going up steep hills. When I accelerate the car just can’t keep up, the odometer starts dropping off and my car has actually stalled out once. When I restart the engine, the car feels fine most times. This doesn’t feel like a transmission problem, but a fuel sensor or possibly fuel filter. It feels as if the engines is not getting enough fuel. On the highways, the Subaru seems to perform fine.
So, I visited another Gas Station and filled up with Mid Grade Unleaded. This seems to fix the problem, except the Check Engine light still appears every once in awhile. I have found that when I fill up with the Unleaded gas from the original gas station, I see the same problems again.
Is the fuel filter most likely in need of replacement and how much should this run me?
I’ve always fed my “fleet” of Subarus (6 so far) mid-grade fuel. If you moved to to a higher altitude, you may to check that your manifold absolute pressure sensor is working correctly. If the port that samples ambient air pressure is blocked, the fuel-air mixture will be off.
On our Outback, I get a check-engine light and the OBD2 code reader tells me it is due to low catalytic efficiency. I can reset it but it comes back a few days later. Get yourself an OBD2 code reader (around $100). Good luck!