1990 Ranger 4.0 Codes 41 & 42

[Mike1971]

Hi,

I have a 90 Ranger 4x4 with 4.0. When I run the dianostics (KOER) I get trouble code 42. Then when I clear the codes and drive the truck till I get the check engine light, I get the trouble code 41.

Lean & Rich? What's Up?

What should I look for?

Thanks!

[Mike1971]

For those interested. The problem was the fuel regulator. At start up it ran the fuel pressure at 30 or so, then 90psi. Changed that and all is better.