Hi. Just looking for some know how before I head to the dealership. I parked up my 2004 blob eye WRX in my garage a couple of months ago. It was running fine, but had the P0420 code with the engine management light on. It’s only done 78,000 miles & still has its original exhaust, so the dealership said it needed a turbo back system to clear the code for the MOT. I parked it up to save up the money. But now when I started it up, it had a really high idle, maybe 2500rpm, & a misfire. Is that all to do with the engine management light issue, or has something else gone badly wrong in the meantime? Any help gratefully received. Thanks

how long did you leave it for being starting it?

It wasn’t run for a couple of weeks, but had been in regular use up until that point. Would it possibly clear the rough idling after a run?

Just give it an Italian tune up, and hope for the best.

My old Sport classic would run bad and have a slight miss fire if parked up for >1week. Every time after she got warm again it went away.