Hey Subaru Nation - I have a 1992 Legacy 2.2 (non-turbo) and I'm trying to diagnose some idling issues. The car runs fine but once its warmed up it begins to surge idle at stops (sometimes stalling). I had a cracked air intake and I replaced it with no resolve and I've cleaned out the throttle body and I'm currently replacing the Idle air control valve with a new one (new gaskets all around). My next option is replacing the mass air flow sensor. My current sensor has 5 pins and all of the replacements I've seen online have 5 slots but only 4 pins?? Does it matter? Will the 4 pin work the same? Also if anyone has any further ideas or sollutions for idling issues - I'm much appreciative. I've also changed out the coolant/thermostat. Thanks for the help!