P3504 fault code p0172
Mar 22, · The P OBD2 Trouble Code is a tricky one to work on. If you have a Flex Fuel vehicle, measure your alcohol content and reset the fuel trim level. Otherwise you'll want to check your MAF, Air Filter and look for vacuum leaks.4/5(5). P/P Diagnostic Theory for Shops and Technicians. When a vehicle has the fault code P and or P, it means that computer can no longer automatically adjust the mixture between air and fuel. Code P applies to Bank 1 and P applies to Bank 2. P Description With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1.