I have an 05 4.4L v8 LR3 and I just started developing a "System too Rich on Bank 2 Error" but only after about 30 minutes once the vehicle has warmed up fully.

P0175-00 (E8) System too rich (bank 2)

I have done a ton of maintenance items recently from O2, MAF, Thermostat, Injectors, Belts, AC, Water Pump. And I am at a loss as to what to try. And it is always after the vehicle has warmed up, so I clear the code and turn off the car and start it again, I will get the code back near instantly and its always on Bank 2. The car develops no noticeable symptoms or issues besides the CEL, the car idles smooth and runs fantastic even when the CEL comes on for this issue.

 

Faulty O2, stuck injector, etc. Bank two is driver side. Have to tried some good fuel cleaner? What fuel are you running?

 

Ive had the O2 sensors fully replaced last year with zero issues and the injectors were done about a month ago but with the weather it has been -30C till recently so maybe the car hasnt warmed up enough. Im running 91 octane. And I havent tried a fuel injector cleaner but I do have some so I will give that a go since Im at a loss.

 

Temps could be an issue if the engine is overcooling. Cold engine tend to run rich but the ECU should be aware. Do you have the grill covered? At those temps I know I would, just to reduce airflow and help engine temps a little.

 

I have watched the temps as the CEL came on and numerous minutes leading up the CEL the engine oil temp and coolant temps were already at their peaks. I did have the front covered for a long time in the -30C temps to try and get the engine up to temp faster but it didnt seem to help. So since then I have removed it and this new issue has only recently started with the slightly warmer -5 to -10 weather. What makes me think an injector even though I just replaced the damn things is the CEL is always reporting on Bank 2 running rich

 

Then you are back to the usual culprits, faulty O2, stuck injector, etc. New O2s do not mean they are flawless, especially if a brand other than Denso/Walker which seem to be the best options. Bosch are pretty bad. Same for injectors, new does not mean perfect. Normally I suggest swapping things to see if the code follows but the upstream O2 sensor on the driver side is hell to get at.

If you can get some live data, that may help.

 

Appreciate the insight, it gives me a starting point to try and troubleshoot this.

 

Fuel injector cleaner did the trick. Ive put about 4 hours of driving and a fresh tank of gas since and the issue hasnt repeated itself. Thank you for the suggestion. I owe you one beer.

 

Good to hear. Lets hope it was just some small bit of fuel varnish that needed to be dissolved and you are good to go. Let us know if it comes back though and we can dig deeper.

 

Hi Cziggy - a couple of years later now and if you still have the vehicle, did that issue ever come back? What brand injector cleaner did you use?

Thanks!