2007 Subaru Outback mystery

So I have been unable to figure this problem out and so had my mechanic, I am starting to think this car is cursed. I have an 07 outback with about 54000 miles on it, a few weeks ago it through a P0303 for a misfire in the third cylinder, thought nothing of it, light went off in the next couple starts and the car was running great. Had this happen a couple more times but only after the car had been out in the rain. Each time the problem went away. Now the car has sat in my garage for four days, I got out to start it and get an extremely long crank but no turn over. Try again and after 5-6 seconds car turns over but is running really rough and stalls out. Disconnected the battery checked hoses, everything looked normal, reconnected the battery and now the car is running fine. I am pretty sure the problem is going to come back, and any help you can provide would be extremely helpful.

There are four primary inputs to the computer when the engine is started cold. These are the Coolant Temperature Sensor, the Crankshaft Position Sensor, the Throttle Position Sensor, and the Mass Air Flow sensor. Out of all these sensors the only one that can cause the engine to be hard to start when cold and can also cause a misfire on any or all cylinders is a dirty or defective Mass Air Flow sensor. Try cleaning the MAF sensor with a MAF sensor aerosol cleaner to see if this eliminates the misfire and the hard starting condition.


I know where the MAF is and all but is that something a novice should try to do? Or will I do more harm than good?

Sure! Go to the parts store and get a can of aerosol MAF sensor cleaner. Remove the MAF sensor and spray the thin wires inside the MAF sensor with the cleaner and let it sit and dry. Then reinstall the MAF sensor. As long as you don't touch those thin wires inside the MAF sensor you can't hurt anything.