Land Rover Repair: service engine soon 00 Disco, land rover discovery, electronic engine management

Question
HI , I have 2000 land rover discovery , a " service engine soon" light came out .I took to a friend , we read the computer and  has 2 code "PO171",system too lien cylinder bank #1  and , PO174, system toolien cylinder #2.
What can I do to help  or eliminate the code .
I have changed the 8 spark plugs and wires like 2 months ago.
thank you very much in advance


Answer
Hi Marcelino,

not much.  You have a fully electronic engine management system and all are controlled by sensors and adjustments are very few.  LR mechanics with a 'testbook' diagnostic device can manipulate some components but there is nothing you can do.  Changing the plugs and wires is about it.

With a system too lean...it could be a MAF sensor that is misbehaving. Best to have a testbook diagnostic done to see which sensor or component is causing this.  When was the last time you had the air filter replaced?

Best of luck,

JohnMc