P0172 System Too Rich Bank 1 Code

unicorncomputer · Feb 23, 2018

2500 SLT 5.7L Hemi

I keep getting a P0172 System Too Rich Bank 1 code and the truck will run like crap, shuddering, feeling like its misfiring or starving for fuel.

I do have an 02 sensor disconnected, Bank1 Sensor1, Cut the wires trying to get it out.

If I take the cables off the battery, let computer reset, truck will run correct and no code for a while.

At 82500 I got the code, reset computer
at 82900 Code came back, I think it was rainy, but don't remember for sure. reset computer
at 82995 code came back, Very rainy and damp, reset computer

I have replaced the MAP Sensor at 82900, I believe it was last spring that I changed plugs and wires. Champion copper plugs.

Being that the truck runs fine after a computer reset, I don't think and injectors, plugs or wires are bad.

Could the 02 sensor being disconnected cause it to do this? I haven't been able to get it out, cut the wires trying to get a socket on it better. Probably going to have to take is somewhere to get it out I guess.

I have an Autel Autolink AL319 Code reader, it does provide some live data if that would be helpful.

Any Ideas?

Thank you,

Steve

HeavyHaulin3500 · Feb 27, 2018

Yes, having the oxygen sensor disconnected can contribute to this issue. There could be some other things in play but without having the WiTech connected and monitoring the adaptive memory/fuel trim it's hard to say what else may be involved. Can you repair the wires to the sensor or did you cut then off near the top of the oxygen sensor?

I would get a new O2 sensor in the pipe before trying to continue your diagnostics. Get some penetrating oil and soak the base of the sensor at the O2 bung. Then, get a cheap propane torch like this one... https://www.homedepot.com/p/Bernzomatic-14-1-oz-Propane-Gas-Cylinder-304182/202044700

Heat the base of the O2 sensor and wrench it out. Next, I would verify that all of my engine vacuum lines are intact including the throttle body o-ring and the intake manifold o-rings.
"Extra" air entering the motor that is un-metered causes high oxygen content to pass across the sensor. When the PCM sees the "Extra" air it increases the amount of fuel respectively creating the rich condition. When the O2 sensor is disconnected the PCM has no idea of how much fuel to provide to start the engine or to keep it running so it defaults to a predetermined value to ensure the motor will start and run, although not very well.

P0172 System Too Rich Bank 1 Code

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