hello all i have a e350 box truck with a5.4 and i am having po174 lean bank2 code could not find any vac leak cleaned mas air sensor changed intake gaskets cleaned iac and all fuel injectors but still have same code!!!
also cleaned throttle body and checked all vac ports on intake all were clear
i also switched o2 sensors and no change any other ideas?

 

Have you checked the fuel pressure? A partially clogged fuel filter?
Double check the PCV hose elbows on the hose assembly, they are known to crack and suck air. Maybe the PCV valve itself needs replacing.

 

fuel pressure 30 psi at idle 42 psi driving. would i get both banks lean if filter clogged or pcv cracked or not working?

 

any other ideas??

 

P0174 = issue with drivers side (Bank 2) Common issues are the tube off of the drivers valve cover to the throttle body. Depending on the year the PCV should be on the passenger side, thats another common issue if it's not seated fully or if the tube from that to the throttle body has a hole and/or broken. A dirty MAF sensor will throw the code (most of the time you'll get a P0171 / P0174 but have seen that to be an issue every once in a while (you can buy cleaner to clean it, look at the small wire and see if theirs any contaminates on it DO NOT TOUCH IT OR YOU'LL DAMAGE IT) Plugged fuel filter will also do the same as the MAF sensor and due to the pressue if looks decent. If you've switched o2's and no change I'd rule that out, and wiring usually throws a code if you have an issue with the o2 or wiring. If you have a warped or cracked intake you can check by using propane with a hose on the end, just run it around the intake - gasket area and if idle changes that is an indicator or brake clean works also but be careful to not cause a fire. If the leak is small you may be forced to have it diagnosed by someone who has a scan tool that can do live data a.k.a. datalogger. Definately follow hose off of the valve cover and make sure theirs no cracks or anything!!!!!