Hello All,
I'm new to the forum, and to Subaru ownership. I picked up a 2009 Forester SOHC, 5 speed, now with 65,000 miles. When new to me the car regularly got 27-28 MPG on the highway going 70mph.
Over the last month or two i noticed it slipping to 25-24-23, then one day the CEL came on, traction control light came on, and cruise control shut off and started flashing.
Got the code checked and cleared with the following results " P2097 Post catalyst fuel trim system too rich bank 1 confirmed" drove the car for approximately 100 miles, with fuel economy around 20mpg highway and then the light came back on, same code. So, i replaced the post catalyst O2 sensor. Drove another 100 miles or so, light came back on. This time i replaced the pre-cat upstream O2 sensor. (also changed the air filter while i was in there)
I haven't driven the 100 or so miles it seems to take the CEL to come back on, but judging by the fuel economy, around 20mpg highway, its only a matter of time and i have not fixed the underlying problem.
Any ideas what other systems or sensors might be causing this issue?
The car other wise runs, drives, idles, and starts normally. Power seems normal. perhaps a little bit of stutter when starting from a stop, but i might be imagining it. it's very slight if anything at all. might just be my clutch action....
Thanks for any help or ideas. I'll update again when/if CEL comes back on.