Codes ford f150 truck Ford po171 p0401 f150 ranger fix engine codes check light 2001 forums source
The ford check engine light: common causes, codes and issues – ford of Fix for check engine light codes: p0401, po171 and po174 List ford winstar trouble codes
Fix for Check Engine light codes: p0401, po171 and po174 - Ranger
Ford obd1
Codes ford list trouble winstar source
How to read engine codes using a multi-meter or test light .