I have an 06 LR3 V6 with 65000 miles on it. I keep getting codes P0171 and P0174 codes. I found other people having similar issues but they seem to have other problems as well or a different engine, so I thought I would try a fresh post.

There appears to be no other issues. Recently my wife got the light on the dash that engine performance was being affected, but that went away. I cleaned the MAF sensor and air cleaner, and found no change. So I replaced the sensor and still no change. I cannot see any difference in performance or fuel economy and it is showing both banks running lean, so I didn't think it is a catalytic converter. (Which side is bank 1 and bank 2?)

I took it into a shop and they did a fuel injection service, checked for vacuum leaks and ran a test on the O2 sensors and they all appeared to be fine. This stupid light will not go away. The shop can't figure it out and I there is no dealership within a couple hours drive. They keep trying to tell me its bad gas, but I must have run 10 tanks of fuel through the thing. (I only use premium.) Any thoughts would be helpful.

Thanks

 

not bad gas but too much ethanol content.

we have this neat little syringe we got from BMW that allows you to look at the ethanol content by taking a sample of gas and then letting it settle and see the ethanol concentrate.

if you think that isn't the case then try switching gas stations.

Land Rovers really don't like Mobil for some reason.

but if you have a physical leak the trick to find it is get a round object that fits the airhose and then take it off the box and tighten the air hose around the object. On V8s we use an oil filter with some tape. Then start it up. The source of the leak will be found by producing a high pitch squeal. find that and you found the leak. If no sound then its the gas.

oh and you can buy the parts from the ford dealer down the street. Its a mustang engine.

 

You shot your self in the "***" by cleaning your MAF. Bosch MAF don't take to being cleaned and you will most likely have to buy another Factory, not after market, MAF to fix this problem.
In the future ask questions before you try things.

 

Thanks for the advice, but I'm still having problems. I took back the MAF I bought from the auto parts store. (It was a reman Toyota unit.) I bought one from a dealership and put that in. It did not help. I have searched for a vacuum leak and still cannot find any leak. I've tried different gas stations.

I did find out that there is an open recall on the emissions system. When I can get it to a dealership hopefully that will help.

If you have any other suggestions I'm still hoping to resolve this.

Thanks

 

Recall won't do crap. Its only for certain knock sensor codes. Not lean codes.

Seriously for the price of the sensor and the amount of sensitivity you are stupid as hell for not buying OE. Two things that should not be screwed with in a vehicle MAF and Oxygen sensors. If you got Oem then you won't have issues and you can positively eliminate them as problems.

and an injector service, Geez that's pure snake oil. Why the hell did you take it to a shop that doesn't know Land Rovers in the first place.

 

Okay, the light went away. As mentioned in my previous post I did put in an OE MAF, I cleared the code and it came right back on. About 4 days after I put in the sensor, the light was still on. I filled up the tank again and got on the highway. I had some cars coming up fast, so I floored it to get up to 70, and as soon as I let off the gas, the light went out and has been out for over a week now. Land Rovers are few and far between here and there are even fewer people who can work on them, so I appreciate the kind help.

 

Just curious did the codes stay away? I will try your stomp on the gas and see if that makes a difference. Same codes don't seem to effect the vehicle running maybe it is just a little testy. The rave cd indicated that rich limit exceeded so I guess that means the system tried to richen up the mixture but failed after reaching the spec limit. Did you also have o2s not ready indicators by any chance?

Also I assume it takes the system of sensors a couple of tries before it decides that things are normal again and turns of the cel.

 

Well I got good news. It seems that V8 engines are not reacting to bad gas and causing lean codes. if you vehicle has over 50k its not a bad idea to do a fuel injector service to make sure the injectors run clean.

Its near impossible to see them actually causing issues.

 

I agree always good to have a check on the spray pattern of your injectors. I use chevron or texaco. Techron was evaluated many years ago and the proof is in the spray. Don't know what the other gas companies are doing but recently I find gas stations that offer cleaners that you can buy when you purchase the gas. Huh.

 

Camper,
Its been over 2 months and 5000 miles now, and the engine light has not shown itself again. I stick to gas stations that do not have ethanol and it seems to be working. (Shell and Chevron seem to be pretty good.) I did not have any codes showing O2 sensors were not ready, and when I took it to the shop they said that all the O2 sensors appears to be operating correctly. I'm still not sure what the exact cause was but changing the MAF, cleaning the injectors and good gas seemed to have gotten rid of the problem. Good luck, I know its frustrating.