1997 GMC Suburban 5.7L Engine P0174, P0154, P0151, P1153 - O2 Sensor Issues and Lean Condition Diagnosis
Thank you to anyone who helps with this issue. I own a 1997 GMC Suburban with a 5.7L unleaded engine (R VIN), currently at 213,000 miles (driving approximately 40,000 miles annually). Maintenance history: - Intake manifold gasket replaced at 60,000 miles - Two new catalytic converters installed directly bolt-on at 5,000 miles - All vacuum hoses replaced, including PCV valve, hose, elbow, and grommet - Full tune-up with AC Delco plugs, rotor, cap, and Magnecor spark plug wires - Fuel filter changed regularly - Fuel pump replaced at 30,000 miles - Mass Airflow (MAF) sensor replaced at 3,000 miles Issue timeline: One year ago, the MIL lit up showing code P0154 — I assumed it was a faulty oxygen (O2) sensor and replaced it. The issue appeared resolved. Four weeks later, the MIL came back with the same P0154 code. I replaced the sensor again, assuming improper installation of the first one; the problem lasted for about 10 months. Recently, the same O2-related codes reappeared — now including P0151 and P1153 (all related to O2 sensors) — along with a new code: P0174 indicating a lean condition in Bank 1. I replaced the O2 sensor again; all codes cleared. Since then, I've been replacing the O2 sensor every three to four weeks. Typically, an O2 sensor fault appears before P0174, but this time, the P0174 code appeared first — followed by the O2 sensor fault. I performed a vacuum leak test on the intake manifold gasket by plugging the valve cover breather and PCV hose openings and checking for vacuum on the dipstick tube. I detected no significant vacuum drop. The vehicle emits a strong exhaust odor while driving, whether in town or on highways. AutoZone and Kragen have started to notice my frequent O2 sensor replacements under warranty — which is becoming concerning. I'm currently trying to avoid taking it to a shop to see if there's an underlying issue I'm missing. Any insights into this recurring lean condition and O2 sensor failure would be greatly appreciated.
Check for vacuum leaks at the intake manifold gasket on Bank 2. Inspect the EGR valve for clogging or malfunction. Verify wiring and electrical connections between the pre-catalyst O2 sensor on Bank 2 and the Powertrain Control Module (PCM) for proper voltage and ground continuity. Are you using high-quality components? The symptoms suggest a potential wiring or circuit fault combined with a lean condition. Good luck — please update us on your findings.