Engine light was on but turned off after diagnostic

I think you have an idea that there may be a possible problem but it could have been a glitch or a sensor that is failing. It is hard to say from here. The key here is that you are aware of an issue. I would listen to the engine for changes, and keep constant watch on fluid levels and guages. Drive it with your senses observing as you go.

[quote:13cb237265="luckyzzz1123"]I have an Acura RSX '04 with well over 100,000 miles on it (I commute about 80 miles for work each day). The engine light recently came on, so I panicked and brought it to the Acura dealership, where they charged $149 for a diagnostic. (Learned my lesson - bring it to a local mechanic next time.) One code popped up - P2647 - rocker arm actuator system stuck on bank1. VTEC issue. Replace oil pressure switch.

By the time I brought it to a local mechanic, the engine light had turned off. I've had 2 start-ups since then and it's still off, car is running fine. Should I still take it in and replace the oil pressure switch for $210? Or can I wait on it without any further damage to the engine? What could the problem have been?[/quote:13cb237265]

Like Bruce has said above, listening to your change in your car's engine is a good way to prevent major damage to engine. I wouldn't say you need to replace the pressure switch immediately. Usually, many dealerships would tell you that you need to replace related parts to the code to make profit. However, I would still listen for changes...and not hit VTEC too often along your 80 mile commute. :) I have a 02 and 2k miles shy of 130,000 miles.

As far as the CEL light going off, I believe the dealership reset it, therefore turning off the CEL. But if it's really the problem, then the CEL will come back on and you should at least take a look at it.