I just purchased my 2002 wrx and am having some misfire issues.. First it threw two cel codes p0301, and p0304 saying misfire cyl's 1 and 4.. i didnt feel any misfiring other than an ocassional hiccup when boosting. i cleared the codes and put about 100 miles on it and the cel came back, it now read code p1312 igntion malfunction or misfire, again seemed to drive fine so i cleared it.. I asked the guy i bought it from if he had any similar issues like this and he told me to get some maf spray and clean the maf, so i did last night. I discovered that the inside of the airbox was covered in white, sandy feeling crud on the bad side of the air filter.. it looked like road salt, i pulled out the maf and it was on it too and all through the intake tubing! I cleaned the maf and the tubing and i cleaned the maf with crc brand maf cleaner spray. At first it seemed to run a little smoother, but it still had the occasional hiccup under boost, i parked it last night content with what had been done but now today it is misfiring badly. Its throwing a cel code p0103 maf circuit high input. Im going to assume it just needs a new maf but before i fork out $300 id like someone elses input too. And... is there any better than oem maf's? I know bbk makes nice mafs for some cars but not for my suby..