1999 Legacy 2.2l was running pretty good. Parked for couple days, then when starting engine stumbles along barely able to get to 1000 rpm. Hunches were fuel or exhaust plugged. Cleaned mass air flow sensor, no change. Intake pipes clear. OBD code is 0440 Evap. Vacuum at idle is 15, drops when giving it throttle. Lots of exhaust flow out tailpipe. Fuel filter replaced 1500 miles ago.
If it is running, I can slowly pull the intake tubing off the throttle body slightly, then it revs better. Let it drop to idle and it dies. Am thinking the mass air flow sensor is bad. Thoughts? Thanks.