engine check light

if the car runs fine and does not stall, i would say he is full of cow patties. honda programs the computer to turn on the light ever 5,000 to 7,000 miles to remind you of oil change time. on some cars you can hold down the trip counter button while turning the key on(make sure the dash lights up) without starting, then off and on again and starting the engine while still holding the counter button. wate until the beeps and lights all go out along with the service light before releasing the trip counter button.

i have a 1999 honda civic DX mileage 189683, and the check engine light went on after i ran through a flooded area in low gear to get home during a typhoon, and then now it also feels like it slams into gear when it shifts into 2nd gear, now i've been told that one of the clutches or bad and since i've been reading that the CPU box lets you know that there something wrong could the clutch really be the problem, and if not, i had changed my stock headers and muffler to aftermarket parts and one of the O2 censors aren't connected could that be the problem someone who knows please reply..