cbrogers

I have a 1993 4x4 pickup (22RE) and I have a fault code 31 which is the mass air flow sensor. I just did a head gasket replacement and this was disconnected during removal of the head cover. The truck idles well but acceleration is rough on start. Do I have to replace the whole sensor to fix this?

abecedarian

Clear the code by disconnecting the battery for a minute or so then reconnect everything, making sure all the intake ducts and hoses are in place as well as the electrical connector to the VAFM (it's not a mass air flow sensor- it's a volumetric air flow meter). Then start and drive and see if the code comes back.

Catlin

I harmed my AFM's inner parts while disconnecting it for a head gasket job. I spent hours trying to repair the delicate wires inside, then gave up. I bought a new one (aftermarket) on ebay for about 100, and it has worked well, real well. My engine has 174,000 and has good power.

mbuhr66

I had this problem after I put a new head on. I routed the wiring up to the intake manifold to close to the EGR valve and it melted the wires. We thought it was the flow censor. Then found the melted wires. Fixed them and runs great. I would check connections and wiring. Electrical parts are usually not returnable.