1997 Ford F-250 Engine light issues

KDJMK5

MEMBER
1997 FORD F-250
306,000 MILES

1997 Ford F250 HD w/ rebuilt engine w/ 80000 miles on it. Truck runs great, no stall, no hesitation, etc. After running for a bit, engine light comes on and after running longer like on the highway then the engine light goes off. It is not on when you first turn on the truck but comes on about 10 minutes. Spark plugs have been replaced, gas caps have been replaced, oil changes have been done. It does have two tanks and back tank has a small leak so I don't put gas in it.
Any suggestions.
Thanks,
Dawn

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

This is going to be a tough one until we figure out what codes are there to tell us what the system is that is setting the light.

If the engine is running properly then we need to suspect this is an evaporative emissions system issue.

However, this is purely a guess until we confirm this.

This year F250 could be an OBD I or OBD II truck depending on when it was built. So here are guides that will help with both:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Please run through this and let us know what the codes are, and we can go from there.

Thanks