(i also posted this in the prelude forum, fyi)

Just bought a 94 prelude from a friend who just rebuilt parts of the engine after he hydrolocked it. (the flap that is supposed to sit in front of the cai to prevent splashing is gone!) Anyway, i was driving home from work and of course its raining hard. On my way home all i could think about was what if i hydrolock this... Well, I was doing ok, steered clear of all puddles and made it to the interstate. At about 5 miles from home the check engine light comes on and I have a pretty good idea why. I make it home with no problems and i didnt notice any difference in the engine, but of course i dont know it that well yet. So i get home and pop the hood and it feels quite hot (at least compared to what im used to in my 92 civic dx (its stock)). I wait a while, come back out and check the oil, the level is normal but it looks a little more clear than normal.. ill double check this in the morning. Then I pull the service connector on the ecu and stick a piece of copper wire in each of the holes to check for codes. But when i turn the key (not starting it) the engine light doesnt even turn on. I wasnt sure wtf was going on so I started it up and sure enough the check engine light, lights back up. If that check engine light is on shouldnt i be able to check for the code? What precautions should i take to ensure I don't have a problem lurking under the hood? I'm a noob so bear with me Any help at all would be appreciated.
(i plan on pulling the plugs and draining the oil to check for level/color. Also plan on a compression test.)

 

If you can't get it to pull a code, take it to autozone or somewhere. They will tell you what code it is throwing. If the car still runs, you didn't get much water in there. If you are worried about moisture, seafoam in the crank case and brake booster line will dry it up. Change your oil shortly after though.