Having troubles with a 1992 Classic running very rich. Plugs look sooty and it's fouling the oxygen sensors. After the "Check Engine" light comes on, it smooths out and runs better. I replaced both sensors with Bosch / NTK from Napa but they get blackened and start giving 44 and 45 codes too. I also replaced the idle air valve / stepper motor but still running rich. This truck sat in a field for three years after an altercation with a deer. Any thoughts? By the way, nice tech forum. Lots of good reading.

 

Hey Thanks

Do you have any drivability problems ?

That statement would point me to rust. Check the fuel filter. It's on the right rear frame rail. take it off and see if a lot of rust comes out. It may be very difficult to get off. They tend to rust up . A kit is available to replace the lines, holder and all. The rust gets forced thru the filter and clogs the injectors open.

Let us know how you make out.