I have a 2003 WRX 97,000 miles, totally stock. It's had a rough idle for some time and was getting worse. Finally threw a P0301 code. Changed all plugs (NGK Platinum) (35,000 miles on them) and coil #1. Also PCV valve and fuel filter (Also 35,000 miles on it). Re-tightened grounds and battery. Runs better, but still some idle roughness. Ran a can of Seafoam through the tank before the filter change. The old filter has very dirty sediment drain out of inlet side. Also ran compression check while plugs were out. 150# to 152# on all cyls.

Ran a monitor check using an ElfScan5 and got a TID$03 ComponentID$03 Failure, but no CEL. It was high according to the table. Reading 27218 when max value is 20775. ComponentID's $01, $02 and $04 were within range although on the high side. Can anybody tell me what the TID codes stand for? I've searched this site as well as the Internet and only found a list for the Legacy 2.5L. According to that list its an Evaporative Emmission Control System Leak (small leak) in Tank Pressure in Mode C (whatever that is??)

Since I had such a dirty Fuel Filter, I'm wondering if this isn't close to what's wrong. It was really dirty, but I don't know where to go from here.

Again, does anybody have a list of the TID codes for the 2003 WRX? It would be greatly appreciated.