Stock truck with rear O2 sensors deleted.
Adaptives reset.
Bank 2 trims make sense.
Bank 1 - B1S1 is reading rich but keeps adding fuel with ST and LT.
New O2 sensor same thing.
Rear plugged in or not - same thing (they are not in the pipe).
Set rear O2 376F and disable P0125 - same thing.
Runs fine in open loop.
stock file, modified file and log attached.
I am down to bad pcm?
Check for exhaust manifold leak on bank 1.
Edit: looking at the log scan, something seriously wrong. Rich bank 2, lean bank 1.
Good luck. Keep us posted.
Last edited by skala308; 05-13-2021 at 04:26 PM.
2010 Jeep GC 5.7 Eagle Head motor, 2" OME lift, cats removed, full MDS delete
And I also have 2016 that kind of does the same thing - just not as bad. Still B1S1 never really does full sweep like it supposed to be doing. Same thing new sensor etc. Even moved it further down stream to see if it helps?
Do these newer 2015+ Dodges require rear O2 sensors functional?
P.S. If it helps any second truck threw code U0401 out of the blue.
The sensor is reading rich but computer thinks it's a great idea to add more fuel! WTF?Originally Posted by skala308
Had it previously been tuned via CMR? You can try a factory flash to set it back to stock via WiTech or J2534.
No it has not. Just got back from HPtuners.
yeah, you have an obvious problem with B1S1... Did you check for your 5 volt reference? Ground as well on that sensor? You've got no movement with the sensor, so I would do your due diligence with making sure there,s no bent pins, pushed pins, voltage reference and ground... Even with LT and rears deleted, you should have some movement like on the other trucks log... By the way, that's classic lean pattern... From what I understand of the feedback system, it's trying to command more air... If it needs more air, it's going to add more fuel till it gets the desired response... It's not getting a response, so it's adding more fuel... If your fuel is right, then the only unknown variable here is the air... Our O2 feedback system is not like any other manufactures... Tread lightly and understand how it works with Dodge... it'll drive the best nuts...
yep, definitly reading classic lean...
you can run without the rears on but I would keep them on till you have this worked out better... The feedback system will use the rear o2 as a backup if the fronts fail... I would think that you would be running OL with the sensor not showing any movement after a minute or two...
Are you saying above .5v O2 sensor is lean and below is rich?
No, anything below .2 is lean and anything above .8 is rich... Everything in between is Stoich... It's just a switch trying to keep you FA ratio where you want it... Your pattern in your logs display a lean condition... Im surprised you haven't gotten a lean code or a cylinder imbalance code yet...It's multiplying the air equation by the fuel factor... so if you need more air it will give more fuel and vis versa... All this assumes your fueling is correct...
B1 sensor is stuck at 0.882v, is it not rich? Or it just sees that it is stuck and adds fuel out of principle?
B2 starts there but then 5% gets pulled and the sensor goes up and down like it supposed to.
Well, I'm not sure what you've done to the truck... Deleting the rear o2 sensors would suggest you've put LT on and/or removed the cats... What exactly have you done to your 2019 Ram? Obvisiously your rear sensors are needed(B1,2 S1,2) to check cat effiency and as a back up if the S1,2 fail... Look idling the truck for a couple of seconds tells us nothing... we need to see the o2 voltages with key on engine off... from there we need to see a Wot shift(1-2) real quick... The purpuse is to see that you have fuel control... Your sensors with the key on engine off should be around 1250-1280mV regardless... when you go into a wot shift and the o2 goes and holds above 900mV I know you have fuel control... You cannot idle and show me anything right off the top... By your reasoning, B1 is rich and B2 is lean... B2 seems to be switching but never really goes + just really stays - B1 just stays +...
B2S1 the ecm thinks it's rich and is pulling a shit ton of fueling, It is stuck at 900mV in the scan... Notice the -numbers for fuel? the reverse for B1S1, Stuck at almost 900mV and is adding a shit ton of fuel... You've done something to really confuse the ECM...
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