2001 Isuzu Rodeo

Computer problem
2001 Isuzu Rodeo Question 4 cyl Two Wheel Drive Automatic 135335 miles

I was driving to work this morning and the check engine light came on. This is the 3rd time in 3 months. The 1st time I had the car looked at and there was nothing wrong other than I hadn't closed the gas cap properly they replaced the thermostat and that was it. They performed diagnostic tests and found nothing. The 2nd time the light came on and went off the next day this happened about a month ago. Then it came back on today. The car is running fine making no noises and no smells. I need to get the oil changed about 80 mile overdue. The only thing that is not working that well is the back windsheild wiper and defroster. Any suggestions? Thank you.
December 11, 2008.

Get the computer scanned for OBD2 code/s Autozone provide this sercvice free and comeback with the code/s this is our starting point

Dec 11, 2008.