sorry it took so long but yes it is true. if you disconnect the battery cable for 2 min it will reset the pcm. any learned values are reset and the check engine light (if on) will go out. if after this your car has a problem idling you should slowly feather the gas while running and it will eventually relearn. if i have been helpful please accept and leave good feedback. i have been giving very good advice to a lot of people and it seems like a lot of them never leave feedback.