2015 Ford F-150 P1151 and P1131 Error Codes: Causes, Fixes & DIY Tips for Pregnant Women with No Access to Mechanics

P1151 and P1131 typically point to vacuum leaks or faulty oxygen sensors. The most common cause is a deteriorated PCV (Positive Crankcase Ventilation) hose connected to the intake manifold. While it's challenging to access, you can try locating the PCV valve under the engine hood—check for softness, cracks, or splits that could indicate a vacuum leak. Although O2 sensor failure is possible, it’s rare for both front sensors to fail simultaneously. Start by inspecting the PCV hose and report back if the issue persists. This step is often effective and affordable.

My husband has experience with classic cars like Impalas, GTOs, or 1950s pickups—he’s confident with those models. But modern trucks like the F-150 have different systems and layouts. I need to explain where exactly to find the PCV valve on a 2015 Ford F-150 so he can locate it without confusion.

The PCV valve is relatively easy to find, but if your husband cannot locate it, further diagnostics—such as checking the oxygen sensors or intake system—are unlikely to be done safely or correctly by someone unfamiliar with modern truck systems. Professional inspection is strongly recommended for accurate diagnosis and repair.

We found the PCV valve and replaced it, but the P1151 and P1131 codes remain. After trying a local auto shop, they confirmed the same issue—no improvement. I’m now considering giving up and taking it to a certified mechanic, as the problem seems beyond DIY fixes.