Got work done at dealer and been a month 02 sensor still inc
Everything else is passed so not sure wtf is going on.the car at one point was renntech tune but I talked to renntech and they said the old owner flashed it back to stock and should have OEM tune on it.
My bank one long term trims are all over the place and seems the ECU is always adapting.I told the dealer it might need an o2 sensor and they said to just drive it.
Is there a way the dealer glitched the ECU to be tuned again to mess up the monitors? Before taking it in all were green ready to go and passed.
However when its all said and done, I believe that you will have to have your ECU reflashed at the dealer or send it back to renntech and have them put the original software in the ECU---I doubt drive cycles will solve your !!
I was in a similar situation. Bought a used c63, thought to be stock but was tuned, and I ended up just contacting eurocharged and had them send me a tuner + v5 with the o2 monitors left alone.
Monitors set within 50 miles.








