Taurus service codes

Does anyone know what "P071 and P072 System To Lean Bank 1 & 2" means?

Thanks for your help

It means the engine has unmetered air going into the engine. Look for a vacuum leak. Are you sure of the P071 and P072 numbers? If both banks are lean it should read P0171 and P0174. P0175 is for rich running.

Does anyone know what "P071 and P072 System To Lean Bank 1 & 2" means?

Thanks for your help
it's probably the EGR ports are clogged or the EGR runner seals on the intake are bad, sucking in air. Just a guess, had a lot of troubles with that.