check engine light? bad gas mileage....

[hootie_ti]

ok so my check engine light just randomly turns on and off, anyone have any clue why? there is no particular time it does this, sometimes it will go a week and never come on then one day it will just randomly shine. AND i got a new fuel pump and filter installed professionally and ever since i have only been getting maybe 16-17 miles to the take, roughly 320 miles. before this i was getting 400 easy.....any ideas?

 

[Sasquatch_Ryda]

Scan for codes before throwing money and parts at it...

Gets the codes and let us know what they are.

 

[scotts90ranger]

yep, easy to do on a '91, it should tell you the problem...