I have a 2006 f-150 with a 5.4. i am getting a P0174 (bank 2 lean). I cleaned the MAF with the CRC cleaner and it was fine for 300 miles and boom the light came on again. So i changed the fuel filter (per the printout from O'Reilly's) and the one i took off was only 1 year old and not stopped up. I am not happy about throwing money at parts that will not cure the problem. Any ideas?

 

check your vacuum lines on both sides of the motor and check out tips from FordTechMakuloco his advise is pretty spot on

 

i looked and they are good

 

Replace the o rings inside the PCV connectors. That’s a cheap money toss and they’re probably needed by now anyway. I chased a random lean code for 1 or both banks and eventually discovered said O-ring missing (must have falled out when I removed the hose during the timing job). I ordered a complete new hose with connectors, ~$23.

 

Do you have your own code reader or are you having it done? Freeze frame will tell you conditions when the code was set. If you have live data you can watch fuel trims and get some ideas. P0174 is a lean condition which will be offset by fuel trims going rich. Gasket leaks are often worse when cold.

If you really want to troubleshoot with live data you can spray fluids at potential leak spots while watching fuel trims. You'll see change if you find a spot.