What is the car? Could be worth speaking to these guys: https://www.facebook.com/totalautomotivetimaru/ Matt Dunn there knows his way around the ECU's from memory. Toyota ones at least (from previous threads on another forum).
I drain mine most times I use it, and there is always some in the tank. Good compressor too that isn't worked hard, so could be worth draining it to be sure it's not contributing. Water trap won't catch it all.
This guy has some good videos, one includes fixing dents, and the process may crossover to help you with your issue.
https://www.youtube.com/user/restolad
Late reply... It was some random road works where they were redoing the surface (where weren't they? lol) we didn't even move for about 15 minutes, then it was crawl for waaay too long. Couldn't even see the works from where we were in the queue.
Mild Mike, I've just got to couch location, which turns out is right up hill. So plan is to get that sussed, then head back in and get food before concert. No idea where though, town is mad.
You got a new cell / ignoring me Dane? Somewhere in Dunedin now, off to claim a couch.
Road works everywhere on the trip down. 30kmh overtaking lanes...