P0172 Error in 1998 Chevrolet Cavalier: Diagnosis and Fixes for Poor Engine Performance
I'm experiencing serious issues with my 1998 Chevrolet Cavalier, specifically the P0172 diagnostic trouble code. The car struggles to maintain speed—only reaching about 30 mph on long stretches without stops, dropping to 5–10 mph in traffic. It sputters badly, refuses to rev properly, and when I floor it in park, the engine stalls slightly instead of responding. I've already replaced the oxygen sensor, spark plugs, spark plug wires, and ignition coils, but the problem persists. Despite these repairs, the P0172 code remains, indicating a lean air-fuel mixture. I'm unsure what other components might be contributing to this issue or how to properly diagnose it. Any insights into potential causes would be greatly appreciated.
What type of EGR valve does your vehicle use—vacuum-operated or electronically controlled? Does it have a MAF (Mass Airflow) sensor or a MAP (Manifold Absolute Pressure) sensor? If equipped with a MAF, are there any holes or damage in the air intake snorkel leading to the throttle body? Additionally, can you check the TPS (Throttle Position Sensor) signal being sent to the Powertrain Control Module (PCM)? There are several potential causes for P0172, especially on a 4-cylinder engine. Knowing your exact engine configuration is key—your vehicle has a 2.2L V4 engine, correct? Good luck and please update me when you get further details or take it to a mechanic.