Check engine light on trouble code 27, replaced front o2 sensor, rear was replaced about 5 years ago, after replacing front sensor I now have 2 codes, 21 and 27; 21 = main oxygen sensor fault, 27 = sub- oxygen sensor signal or heater circuit fault. Would replacing rear sensor fix the problem ? Or do I need to do something else?
have the same problem?
Monday, September 6th, 2010 AT 12:53 PM