I have a 2013 Ford Explorer. It is sending a p219b code for a fuel/air ratio imbalance. I have cleaned the MAF sensor, air filter, did a tune up, and checked the fuel injectors for any external leaks and did not see any. What is the best diagnostic approach for this code?
Pressure test the fuel pump, dead head, idle and running down the road and engine off. Does it make enought pressure? Does it leak down after engine is turned off? Injectors can leak internally into the engine. Try this and post back.