P1131 and P1151 Error Codes on Ford E150 Van: Common Cause and Diagnosis
I recently encountered two error codes on my 6-cylinder Ford E150 van: P1131 (HO2S B1S1 indicating lean) and P1151 (HO2S B2S1 also indicating lean). Both oxygen sensors are reporting a lean condition. My question is whether this dual sensor fault is common, or if there's another underlying cause that should be investigated?
When two oxygen sensors report the same 'lean' condition, it strongly indicates a lean mixture in the engine. A vacuum leak is a common issue on Ford E150 vans—particularly in the PCV hose and elbow area. Additionally, check fuel pressure using a gauge to rule out low fuel pressure as a contributing factor.