My 86 4runner has been throwing a check engine light lately. It lights up for a few seconds and then goes away, so I never have the time to check the code. It never happens at idle, only when cruising. Any ideas?

At first I thought it was the O2 sensor, I changed that and it still hasn't gone away. Oil pressure and coolant temp seem fine on the gauges. Thanks for the help.

 

Check you oil level. You can still have decent oil pressure even if it's a quart low. Also, check your gas cap, and make sure its on tight, or check your exhaust for leaks. And if this doesn't fix it, you can always get a code reader, and read the codes.

 

If your truck has thrown a code then it has stored the code in the computer.
Jump the connectors (pretty sure its e1 to te1) with a paper clip then turn the key to the start posistion.
count the blinks and then decifer it.