I bought a used 99 Forester S and the check engine light has been on and off (mostly on) for over a year..it always reads the same code P0303 misfire on cyllinder 3. The light always flashes before staying on indicating it is detecting a misfire. I usually clear the light by disconecting the negative terminal. I have had the dealer where i bought it (not a subaru dealer) and the local subaru dealership try to deal with it..I have had 2 new sets of plugs,and wires, 2 new coils.. but the problem is still there..it seems to run fine, plenty of acceleration and very smooth running, except when idlling, you can occasionally hear the put put of a misfire from the tail pipe.. any ideas anyone...