it does not tell you the oil is no good or the condition of it, just a mileage reminder basically and the codes are the same as autozone -pepboys it does not tell you what the code is it will be like p0171 for example. last question is hard to tell , what code did you have pulled? a lot of the mafs code still go down to being a leak in a hose or just dirty maf sensor. On my daughters car it was throwing a code for a bad maf I cleaned it and it solved the problem.
all in all it's a good tool and worth the 59.00 bucks in my opinion

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2001 Ranger Edge 4x4 , Stepside,FRF decals, 4.0L SOHC decals, Primus IQ brake controller, curt 2" rec. hitch, custom winch mount,
Tinted glass, Yellow BUGGMAN OVALS a real treat to have. OHC, CB, night vision goggles, 36" periscope,
DiabloAmarillo = The Yellow Devil