My p0171 CEL woes happened way too close to tag renewal for me to try and deal with it myself. I took it in to SOK to avoid missing deadlines and having expired tags. ...problems arose while my car was in service. I just want to say they recognised things and made sure I was taken care of in my mind. I will visit them in the future.
Lydia and Steve at the service are really nice people and always want to help find the best option for you.