I have a severe miss that literally shakes the whole truck at 25-45 mph. When I reach 55 mph, it smooths out fine. I have installed the following new items with no change: distributor, plugs, wires, and coil.

I have a cheap de-coder from Oreillys that throws the following codes ( #157 Maf Air Flow sensor fault, low voltage) and (#172 HO2 Sensor fault lean).

Any suggestions or comments would be greatly appreciated.

Thanks

 

The 94 model did not come with Mass Air from the factory. I would check the O2 sensor, it is most likely fouled.

 

Ok thanks, I'll check it.