I have a 1987 Chevy 1/2 ton, 4x4 PU, a automatic transmission with OD. Throws out a code 43 everytime I use the passing gear, or if I have it on cruise and go to pull a hill. Sometimes it makes a noise like I'm useing cheap gas.which I'm not. I've had this problem for some time now, it's a bit aggrevating !!!!!! I could use some help. RDSOFA
I don't think you're supposed to use OD to go uphill... You can buy those books for the codes, it'll have it in there if you don't know. http://my85silverado.tripod.com/
That would be a engine knock sensor...the electronics is attempting to adjust the timing and is detecting a knock (detonation) withing the cylinder(s). probably just the OD....
