2012 GMC Terrain
Mileage
148,639
Service Date
5/24/2024
Services Performed
- P0171-fuel system lean bank 1 P0420-catalyst system efficiency too low bank 1 Long term fuel trim at idle is at 16, short term is between 2 and 10. MAF sensor is reading 2 grams per second at idle, should be closer to 4. Checked for vacuum leaks-none found. Unplugged maf sensor, fuel trims dropped to near zero within 1 minute. Recommend replace maf sensor and recheck. Monitored front and rear oxygen sensors. Found rear sensor mirrors front sensor under load, indicating failed catalyst. Recommend replace catalytic converter. Replaced maf sensor, cleared codes. Test drove-ok.
Elissa A. gave our service a 5 star review on 5/24/2024
