Subaru Repair: Forester hesitation and MIL, mass air flow sensor, mass air flow


Question
55K miles.  Check engine light on most of the time.  Car hesitates occasionally, and is down on gas mileage.  Problem started just after passing NJ state inspection, but I did notice both the CO and HC values were just under acceptable limits, and much higher than our other cars.  ProScan (generic scan tool) gives fault code of P3325, which doesn't seem to exist.  Replaced front oxygen sensor; didn't correct problem.  Plug wires check good on resistance.  Changed plugs recently (NGK iridium). Checked coil with puzzling results: Secondary readings are within specs, but the primary side (at the connector) gives readings in the MEGOHMS, when they should be under 1 ohm.  What would you do next?  Thanks, Frank!

Answer
Hello Pete,

   Not sure what year you have, but call your local dealer and see if there are any open recalls on your Forester. '99 Foresters had a recall on the Mass air flow sensor, and '01 and '02 Forester had an ECM reflash recall. Start there.. I hope this helps.

                                 Thanks,
                                    Frank