vidsolve

its a 2010 forester, non-turbo model.

Aloha subaru experts. i read a really great thread where a guy had same code and found out from the shop that it was a bad fuel injector on #4 cylinder. His problem was CONSTANT, mine is intermittent but its almost constant. when the mis goes away, it runs flawlessly. 85k miles, superb maintenance, new plugs and wires at about 68k miles, the master mechanic finally said this regarding the guy with the constant misfire on #4 cylinder: Mike, I'm not sure I can rise to your challenge to ''account'' for the apparently weak spark to #4, so how about some conjecture? If you reread the last paragraph of my post #29 in this thread, I was wondering whether the ECU was providing a compromised ignition pulse for #4. The ECU determines EREV (engine speed) from pulses developed by the crank sensor and reluctors on the sprocket, and uses that data to influence ignition timing and dwell. If the ECU detects a drop in EREV a sufficient number of times after a particular cylinder is supposed to have fired, it ''assumes'' that the cylinder is misfiring and sets a code. Now for the conjecture -- perhaps the detected drop in EREV causes the ECU to markedly change the ignition dwell for the affected cylinder, thereby affecting the spark intensity. not sure where i should start. thank you for your help!