2000 Ford Windstar P0172 Code: Diagnosis and Solutions with P0153 and P1132 Codes
Hi everyone, I'm currently troubleshooting a 2000 Ford Windstar that has been displaying the P0172 code (System Too Rich Bank 2) along with intermittent P0153 and P1132 codes. The P0172 code is the most persistent. I've already replaced the MAF sensor, DPFE, TPS, and intake air control (IAC) valve—last updated six months ago—and have confirmed that fuel pressure regulation works properly using a hand vacuum pump. The vehicle idles roughly at idle speed and exhibits poor acceleration response; it often backfires during startup or when accelerating gently. However, once the throttle is fully pressed, performance improves significantly. I notice a slight surge around 2000 RPM (~40 mph) on mild uphill inclines, but no visible vacuum leaks have been detected at intake gaskets or hoses. The engine does not show signs of fuel or air leaks that would typically cause lean conditions—so I'm puzzled by the rich code. I've also verified fuel pressure and found it within Haynes manual specifications. Despite these efforts, the issue persists. Any insights into potential root causes for a P0172 code in this model? Thanks in advance for your help!
Intake gaskets can still leak even without showing lean codes—don't rule them out. Check the oxygen sensor readings under lean conditions and verify fuel pressure and bleed-off time. Surging is often a strong indicator of a vacuum leak.