My 99 Disco II 111k milesis showing these codes
P0171 - system too lean (bank 1)
P0174 - system too lean (bank 2)

Could this be the 02 sensors going bad or a result of the previous owner not using premium fuel?
The codes reappearwithin 50miles or soof being cleared and driven and almost always after it has set overnight.

Thank you for any advice.

 

What are you running for an air filter?

 

Hi Mike,

I've only owned it for a week and I haven't changed it. But I checked and it issome kind oforange paper filter.

 

Good, at least it is not a K&N which will usually kill your MAF which will throw 2 lean codes and one 4th gear out of ratio code.
You may still need a new MAF, let me know if your exhaust starts to smell or if the truck starts having shifting problems for either 4th. gear or lock up.

 

I noticed when I checked the filter it looks like the MAF has been replaced. There is a bosch installed now. Could this be the problem?

 

So does anyone have a recommendation fora brand of air filter?

 

Bosch is what is supposed to be on there. If you can find a good experienced Rover mechanic you be able to test it, but it will probably cost you as much to just plug and play a new one.
Wait though until you see if any more issues show up.

 

What would the exhaust smell like with the MAF going out? And it does shift funny sometimes. What would itshift like with the MAF going out?
Thanks again

 

The exhaust just has an off smell and the tranny will feel like it is hunting for 4th gear and lock up, kind of uncertain shifting.

 

The "incorrect 3rd gear ratio" code showed up today. Is this a sign of the MAF being bad?

Also, I am getting a little moisture dripping from the tailpipe whenthe vehicle isfirst started but not when its warmed up and a little smoke that also goes awayonce it is warmed up.
Has anyone else experienced this?