Im out of ideas trying to solve a system running rich bank 1 and 2 code.

Recently replaced injectors, fuel pressure regulator and fuel pump trying to solve this issue. I just replaced all o2 sensors (2 months ago) which eliminated the code. Now that code is back.
Any ideas???

 

Post the exact codes, please. Can we assume by your username it's a 1999 F150 with a 4.6? Manual or automatic trans? 2wd or 4wd?

 

p0175 and p0172.

Yes, 1999 4.6, manual, 2wd

 

Replace the air filter and clean the MAF sensor. Change the oil and make sure the engine is running at normal temperature, not too cold.

 

Still no luck, still have the p0175 code. I cleaned the maf, and removed the aftermarket CAI and reinstalled the factory air intake with a new filter. Im out of ideas unless there is a vacuum leak coming from the intake manifold somewhere.

Bank 1 fuel trims are within 0-10% +/-
Bank 2 fuel trims are within 0-16% +/-

 

Have you verified it's not running too cold? The factory gauge is almost useless.

 

data stream screen shot says 85 Celcius / 185F

 

The codes set when the Fuel trims shift to 25% or greater to the Leans side trying to correct for to much fuel.. *
With all that has been replaced, what is the actual fuel pressure? No more than 40 psi.
Has the Mass Air Sensor been cleaned?
Thermostat, if at 185 is still too cold. Should be running near 195. Replace it.
Running fuel higher than E 10 will also shift the Trims.
Fuel Trims react to cooling system temps.

Only way the codes are set is too much fuel injected the Ox Sensors are detecting. This is where Fuels greater than E10 carry more Ox in the exhaust the sensors detect and cause the Fuel Trims to shift.
This lowers fuel injection amounts by narrowing the injector pulse width trying to correct it. *
Good luck.

 

I replaced the thermostat a few months back, it wasnt fully up to temp when i took a screen shot.

It runs at 200F last time i checked.

The MAF was replaced, plus i removed the aftermarket CAI and reinstalled the old factory air intake with a new filter.

Did a hard reset after installing the new MAF, still have a p0175 bank 2 code. It took a few days for the code to be thrown.

Ive only ran 87 octane gas.

I tried to release fuel pressure via the fuel rail schrader valve, but no gas spilled when the valve was pressed. Schrader valve could be stuck. Ive got a spare valve and tool to remove it.

Is there any other way to test fuel pressure? Could a better scan tool give me a fuel pressure reading?

 

I don't think there is any way to test fuel pressure on your generation truck except with a gauge. Something that can cause rich readings is a leaking fuel pressure regulator. Pull the vacuum line off it and see if any fuel drips out of the line.

 

If the fuel return line is blocked or restricted, it will raise fuel pressure.
There is no other way to measure pressure but using a Gauge on the test port.
Anything that raises fueling will run engine rich.
Intake Air Temp sensor can also do it if out of normal range of operation.,.
Good luck.