Just bought a used 2004 Accord and had the check engine light pop on on the way home. Errors came up as engine misfires. Dealership said it was most likely water as they had just hosed down the engine before we bought it. They reset the error, we drove home and it popped on again. Took it back and now they're telling me it was because the ECM needed to be updated. Am I getting shafted? Any suggestions?

Edited to add: It's a V6 sedan.

 

Updated ECU:lmao: Check your spark plugs.

 

That's what I'd check first. I rinsed off the engine in my wife's nissan altima and got a bunch of water down the spark plug wells. Made it run like crap. If they are wet, dry them off and clean em up and everything should be good. I don't know if that would give a CEL though. Never did with her car. Otherwise, hound the dealership until you get it fixed.