Code 31
 

Hello everyone,

Im new to forum and am anxiously looking for some help/guidance in troubleshooting my supras problem. Earlier today after returning from the store I noticed that as I was going into my parking spot at home, the car's rpms began to drop and nearly caused the engine to shut off. As this was happening the engine light flickered on and off and then remained lit. I performed a diagnostic and retrieved a Code 31 that according to the TSRM, concerns the air flow meter.

I later went ahead and jiggled the AFM connector wires to see if maybe there was a problem in the wiring while the car was idling in park but I didn't notice anything out of the ordinary [no rpm drops or spikes etc]. I went back inside the car and noticed that as I tapped the gas pedal in Park, the rpms dropped maybe 1-200 rpms everytime. The engine does not shut off however. I wanted to see if there was any hesitation or rpm drop while in reverse or drive so I moved the car back in forth in my apt complex parking lot but everything seems fine there.

So what do you guys think is causing this? Should I be checking other wires or should I just go ahead and find another AFM as this one may have just seen its final days??

At the moment, the only "mods" on the car is a K&N intake and custom cat-back exhaust. I suspect the K&N intake may be to blame here but I'd like to hear your thoughts on the matter before I go taking anything apart. Im not very car savvy so I don't want to mess anything up.

The car is a 1991 Turbo AUTO with 122,XXX miles

Any help is greatly appreciated