02 f150 5.4 2v Rich Condition Both Banks Closed Loop. LTFTs both towards -20% will post pics! Drop near zero with lean condition induced. No codes trims right under threshold and no pending codes.So, heres the rundown I have fixed multiple issues on this vehicle not all having to do with this current issue but am listing parts. No major exhaust leaks, good exhaust flow by feeling tailpipe. All monitors I have seen ready except the evap system. I do have worn valve seals and slightly high oil consumption but nothing very alarming, PCV system all good. Fuel pressure regulator checked and functioning, as well as EVAP purge solenoid. New Injectors 1a auto TRQ brand rated at 44psi i believe and possibly issue but have ran tests and unlikely. Fuel line pressure has not been checked New plugs, COP boots and wires only, CHTS within spec but cycling between hot and cold constantly is this normal? TPS and IAC is good. Throttle plate has been cleaned and body inspected, Checked air filter and intake for cracks or blockages all looks good MAF has been extensively tested and all data appropriate for my region and temp as well as airflow. My scanner won't do a power balance test keeps failing but I did the poor man's unplugging COPs and no noticeable differences. 02s all oscillating as they should pics of that and fuel trims below thats me dropping from 2500 RPM. Truck drives great All fuel trims perfect when on the gas and only very slight almost not noticeable stumble at idle only but fuel trims the same at a stop coasting or in park.





Edit; So after much testing and talking to many people and rulling out a evap solenoid this has been fixed. I got a warranty replacement and did my injectors again, in the process while depressureizing the fuel line there was alot of pressure, so used Compressed air and confirmed return fuel line clear, also noticed my throttle body was a little loose on a bolt but I don't think this had any affect. Put it all back together and fuel trims are perfect excited to see milage!

 

You need to be using 19lb injectors not 44lb injectors.

 

I think that's just their max rating to stay within spec, rail pressure according to spec maxs at about 44 under load so makes sense I thought. injectors were matched to engine code L

 

It came from the factory with 19lb injectors.

 

Check the purge valve, maybe it's stuck open allowing fuel vapors into the intake at all times.

 

It looks like you're mixing up the injectors' rated flow rate number (in lb/hr) for the maximum rail pressure that 1A Auto (stupidly) chose to describe the product they are selling. Since the OP didn't identify the actual parts he used, we don't know what they are. That said, if they were injectors with a higher than expected/specified flow rate, they would definitely contribute to "rich" trim issues.

Want to explain what that actually means?

What is the measured fuel pressure at the rail?