I have a 2001 325i, after failed emission/check engine light, had the thermostat, secondary air injector valve, & an O2 sensor. Check engine light is off and the shop told me to run it a hundred miles before retesting, unfortunately, I have run it 200 plus miles, checked twice and monitors all three have not reset. Mechanic is scratching his head - said something about faulty memory. I am at my wits end and need to get this through emissions and back on the road. What could be the problem with the monitors? Have driven in all different conditions, including cold starts and on 3/4 take of gas.

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This post was auto-generated based upon a question asked on our tech article page here:

Is the vehicle taking a long time to warm up? If so, the monitors will not run. If it is, there may be a misfire or fuel trim issue stopping them from running.

- Nick