The engine warning light came on on my 2007 WRX estate Impreza on Saturday, had it plugged into a diagnostic machine yesterday & it reset & the light went off.
Unfortunately I've come to go to work this morning & it's back on. The garage said the error was the air pump valve in Bank 1 is stuck.
After having a quick look on the web I believe this is not an important part of the engine but can be very expensive to fix.
It also seems that there is a way to map the air pump out of the ECU which would then correct the fault or put blanking plates on it somewhere.
Any help would be greatly appreciated. After spending £600 in November having the diff bearings replaced I really can't afford to much expense.