2004 Nissan Sentra P0420 P0731 P0732 Fault Codes - Car Runs Poorly with Stalling and Shaking

Model: 2004 Nissan Sentra Fault Code: P0420 Posted: 2006-09-30 10:22

My son's 2004 Nissan Sentra Limited Edition (1.8L engine, automatic transmission) is showing three diagnostic trouble codes: P0420, P0731, and P073-32. The car starts and runs but performs very poorly—experiencing severe stalling, shaking, and hesitation during operation. It seems like the engine is flooding with excessive fuel. I need help diagnosing these issues to determine their root causes and possible fixes. The P0420 code suggests a catalytic converter efficiency problem, while P0731 and P0732 indicate transmission-related issues such as incorrect gear ratios or sensor malfunctions.