help with a PO 1151 code

[bobbie58]

My 1998 ranger with a 3.0 2wd keeps a pending code 1151 popping up ,i replaced the bank two oxygen sensor, the map sensor , the injectors, my fuel regulator and fuel pump, says it can be a vacuum leak on the engine or my pcm, my fuel pressure is about 68 , could it be the fuel regulator or the fuel damper that connects to the fuel rail?

 

[RonD]

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2

Bank 2 is drivers side on a "V" engine
Upstream is the O2 closest to exhaust manifold on that side

Just so we are all on the same page

O2 sensors generate their own voltage, AFTER they are heated up above 600degF
.1volt means high oxygen in exhaust, which is called lean
.9volt is low oxygen in exhaust, which is called rich
O2s just see oxygen not fuel
The computer adjusts fuel injector open time to try and keep upstream O2 sensor voltage in the .3 to .6v range

P0174 System too Lean (Bank 2)
This is the generic lean code, most common "lean code"
This one means computer is having to add more fuel(at least 15% more) to that side of the engine to get O2 sensor voltage "switching" at the .3 to .6volt range

P1151 means even after adding more fuel the O2 is not "switching"
This would mean there is ALOT of oxygen in the exhaust on that bank/side

Fuel pressure or MAF sensor wouldn't be the issue since that would effect BOTH banks of a "V" engine

So its something specific to that one bank
Exhaust manifold leak, this SUCKS in air doesn't just let exhaust out
EGR tube leak, if its on that exhaust manifold
Misfires on that bank, you don't mention running issues???
Clogged Cat converter, if that bank has one that's not shared, but would expect running issues, low power
Lower intake manifold air leak on that bank, but would have to be a big leak for No Switching


I would buy an OBD2 Bluetooth reader, $15-$20, these work on ANY vehicle 1996 and newer not a Ranger or even a Ford thing, ANY vehicle
And look at the live data from the O2 sensors to see what the computer is seeing
See if the Drivers side upstream O2 is indeed stuck at 0.0volt, no switching lean

 

[bobbie58]

its a new pipe with the two cats, i had JBA headers on it and the pipe from the egr would not tighten up where it mounts to the header , so i put the stock exhaust manifolds back on, it has a cool air intake on it and the rubber part where the air temp sensor mounts into it had cracks in it, only running issue is pulling hills,maybe ill reseal the exhaust manifold , i have a Autel Autolink AL319 and forscan, thank you for the help,,,