I have recently purchased an '05 r53 with about 110,000 miles. The mini has a 17% pulley reduction, 1 step colder plugs, coil overs, and exhaust. I have not done any of these mods as they were done by the previous owner. I have now been receiving multiple codes, p0171, p0131, p0130, and p0455. My initial thought was to replace the B1S1 o2 sensor as one of the codes suggested, and replaced the gas cap as the original gas cap o-ring was dry rotted. I am still receiving the p0171, p0131, and p0455 code. After replacing the o2 sensor and putting vaseline on original o-ring all of the codes went away for about two days, came back on, on way to inspection. I am not sure where to go from here. I have been considering taking it to a local shop to get the intake system and evap system smoke tested. Any suggestions before I commence?

 

I would get inpa an hookup cable. Then reset fuel adaptations with INPA.

 

for the o2 sensor, did you buy the NTK sensor? If not, there’s a high probability that is the source of P0131 and P0174.

For P0455, since you replaced your gas cap, inspect the evap purge solenoid in the engine compartment. Passenger side near supercharger horn. You’re looking to make sure it is connected and no cracks in the plastic pipes.

 

The reason it goes off for a few days is that the system with an issue is not used during every trip. It sounds like the evap system, possibly the little pump in the back that drives it.