Hi I am new to this site and need some help. I own a 2001 land Rover Discovery SE-7
and I get codes of P0714 & P0171 scaner says that, Bank 1 sys to lean and Bank 2 sys. to lean. Does anyone know how to Fix it? I put in and new air filter no help. I just don't know what to do to fix it. Please Help ETH

 

how many miles?

 

Get a new MAF sensor. A fourth gear ratio P0734 code and 2 lean codes are very common for that.

 

Most likely you have a MAF failing. How often does the air filter get changed, if it a paper air filter or a K&N style?
You will be best oof to leave it along for a few days, drive it pretty hard and see if anny additional codes pop up to justify a MAF replacement.

 

In addition, you may have a leaking lower intake gasket. I have experienced this problem when the lower intake bolts are loose / Vee gasket failed. This allows un-metered air to get drawn into the combustion chambers. If the rear part of the gasket has failed than you may get additional misfire codes for cylinder 7 & 8 because antifreeze will be drawn into the 7 & 8 intake runners in small amounts.