The engine light on my 3rd gen S keeps coming on. It only comes on after the car is warm. I checked the ecu and it blinked 4 times. I checked a few sites and it's my vaccum signal switch. What do I have to do to fix this problem? Cus i have to get my car smogged and they will not smog it if the light comes on.

 

when any of the codes on that generation prelude flash on the ecu, the first thing the trouble shooting tells you is to reset the ecu. i don't know how to reset the ecu for your model, but the 2.0 and 2.1 mpfi models use the underhood fuse for the clock. take it out for ten seconds then put it back in. try that. start the car and if the code is still there you could always try disconnecting the battery. if it still appears after the car has been started with the disconnected battery then i don't know what to do. it sounds like the vacuum control is not working right or there must be some sort of sensor near that that you will have to get from honda. hope this helps at least a little bit.