Land Rover Repair: 2000 Discovery II Service Codes, land rover discovery, combustion cycle

Question
I have a 2000 Land Rover Discovery II.  The service engine light came on and I had it checked out where I bought it (Ford Dealer - bought it used).  The codes were PO171 and PO174.  From what I have found (Ford dealer didn't have a manual, I had to look on the internet) they are for "System Too Lean (Bank 1)" and "System Too Lean (Bank 2)".  Can you tell me what this means and if there's anything I can do without taking it to the dealer?  Any help would be appreciated.

thanks.

Answer
Hi Amanda,

the OBDII codes you mention seem to indicate fuel mixture related problems.  These codes can be triggered for a number of reasons and all require expert diagnosis.  It could be as simple as adjustment of fuel to air ratio; a problem has been detected within the combustion cycle of your engine and needs attention; exhaust problems; fuel intake is being restricted.  

The only thing I can suggest, besides taking your Disco to the nearest LR dealer, is to consider when you last had a tune-up performed.  Fuel filter, air filter, spark plugs and wires should be changed every two (2) years unless you have high mileage.  

A dealer would be more familiar with your engine and should know exactly where to look for problems associated with 171 and 174 errors. They are usually associated with other component problems - like sticking valves or a vacuum leak.  Again, this work requires a dealer.   

I wish you luck, Amanda, on this problem.  I dread having to take my Disco to the dealer and always wonder "how much it will cost this time?".

Regards,
JohnMc