Check engine light comes on when driving over 50mph and over 2000rpms on 1993 Ford Explorer

My check engine light comes on when I reach 50mph on the freeway. If I slow down and let the rpms get below 2000, the light turns off. Around town it's fine, only happens on the freeway.

by in Portland, OR on January 20, 2011
3 answers
ANSWER by on January 21, 2011
Need to get the code that is being set by the check engine light, it will be there in the computer, even if the light is not currently illuminated.
ANSWER by on January 23, 2011
Hey big Pearl bring it by my shop on 20th and se stark and ill get you the code for free.
ANSWER by on July 09, 2013
Could be the o^2 sensor best fix for that is use a higher grade of fuel