I've recently converted to e85 and a return fuel system and have my drivers unplugged. As a result I'm getting P1233 and P1234 DTC'S, in doing searches I can't find any info on turning them off. Will these codes cause any future problems?
Smog will be a huge issue with those codes. I believe a good tuner can turn them off for you.
Are you referring to this, FPCM - Fuel Pump Control Module ?
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No need to use them, they're not controlling the fuel pumps anymore. I'm just using the power source on the left plug that goes back to the PCM to power the pumps.