04 Liberty Bank 2 Too lean.......

[Davidvan326]

I have a 2004 Jeep liberty with 3.7 L engine. I have had a bank 2 too lean issue for quite some time now. I have massive quantities of unburnt fuel coming out the exhaust. I have checked everything under the sun, with the exception of the computer. Is there a way to check the computer without buying a replacement?

FYI.......all new O2 sensors, all injectors cleaned and functioning, all coil packs firing, pull valve covers to check for rocker arms engaged, checked for Vacuum leaks, fuel pressure is good, don’t know what else to try.

Thanks
David

 

[03GoingStrong]

Sounds like you've checked or changed most everything. I feel your frustration. Might find some other ideas at this link ... https://www.700r4transmissionhq.com/p0174-jeep-liberty/ ... but I think you've tried most all that stuff.

That link covered the basics, but what if those fixes don't get it, like in your case? ... this link will take you further along ... https://repairpal.com/obd-ii-code-p0174

 

[LibertyTC]

With mega un burnt fuel should it not be a rich condition? Engine light on? What are the code #s ?
You replaced the 02 sensors, with what brand ? Jeep only likes NGK/NTK 02 sensors.

 

[Davidvan326]

With mega un burnt fuel should it not be a rich condition? Engine light on? What are the code #s ?
You replaced the 02 sensors, with what brand ? Jeep only likes NGK/NTK 02 sensors.

Bank 2 is showing lean..... code P0174.... so computer is dumping fuel into cylinders at full flow to try and compensate..... fuel is getting there... Just not burning. (I’m assuming it just too rich to burn it all) Coils are firing... plugs are properly gapped and . NTK sensors.... I’ve tried swapping sensor around (thinking one of the new ones my be bad...). Still runs rough... smells crazy rich and throwing P0174 (bank 2 Lean)

 

[DadOSix]

Couple of thoughts:

oem/ ngk sensors?

1- wiring at the bank 02 sensor. Frayed, shorted?
2 - are these upstream sensors (before cat) or downstream?
3 - did you try to swap right to left (assuming the sensors are the same?
4 - do you have a scan tool that shows your fuel trims?
5 - fuel rail pressure ? Too low = lean. (I think it would show on both banks though)
6 - vacuum leak? (Too much air = lean)