My 1999 F-350 has been throwing codes PO135,P1131 and P0171. I have changed the 02 sensors and repaired 1vac. leak? The injectors and coils have about 230K on them? I also notice that when the AC is on I can smell fuel when at a stop light? I have checked but cant find any fuel on the motor. Do injectors and coils have a standard life? I have been tring to buy a better scannor but have not been able to find one in my price range. Any sugestions?? THANKS

 

it all has to due with bank 1 which is passenger side of engine,make sure you replaced the correct O2 also check the fuel pressure regulator

 

Thanks. I have already verified the o2 sensor but will check the fuel pressure at the fuel rail?

 

Checked the fuel pressure at the rail and it was at the low side 27 to 28 psi? My repair manual notes it to be between 28 to 35 psi at idle. When I ran the motor up to about 2,500 rpm with no load it droped to about 26 psi? I think I moght check the ohm readings on the injectors on the left side of the motor? Let me know what you think. THANKS

 

Maybe something in your fuel system causing a pressure drop. Have you changed the inline fuel filter under the cab?
Also try running some seafoam for a tank and see if that helps out at all.

 

While this might not be directly address your problem running some Techron Concentrate in your tank every 3K miles or so helps keep all the fuel-y bits clean.

Not bashing Sea Foam but I'm a bit more experience with the Techron.

 

I have run Lucus fuel cleaner thru it on a regular bases and the fuel filter has about 5K on it. I have changed the fuel filter a couple of times in the last 25K?