Hey,
I'm new to this site and would appricate any help you might be able to give me. I know enough about engines ( older cars not new ones ) to get me in trouble, so here goes. A couple of weeks ago while at a stop light, without warning, the engine started idling very rough and the service engine soon light came on. The car continues to idle rough and revs up and down. It is driveable, but when you put it in reverse it BANGS into gear. I tried one of those OBD2 computers on it and it reads P0171 System too lean ( Bank 1). I have been told that possibly one or two of the oxygen sensors might be bad or maybe ( I really hope not ) the Powertrain Control computer maybe bad. Has anyone else had this problem. I appricate your help.