Going full throttle while running lean will cause the car to go into PE mode. I would stay out of the throttle for a while will you figure out what's wrong, which is probably a vacuum leak as mentioned before or an O2 sensor.
PE mode is for when you go WOT. Running lean before that will actually just add more fuel in PE mode.
01 gtp-big cam e85 dd 78dodge- guzzling fuel 05 cummins- rollin coal
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