"PGM-FI" lighting up,,,

[Accordianted]

:bh:

FOr some reason, ever since i bought my car, the PGM=FI light goes on after the car drive the car at around 1700-2000 RPM for periods of 5 minutes or longer. now, in the area I live in, that's around a light cruising speed. I just replaced my head gasket (by myself) about a good month ago. What possibly could b e wrong?

[anchovies]

look under the driver's seat, open the small window and count the number of times the led blinks (put key in ignition 1st) then check in the FAQ for the code.