Mixture to lean

[kevh]

engine light came on today my son has a snap on diag unit it came up with "long term fuel mixture too lean" does anybody know what this means?
also found a pipe that has a Y piece on one part goes to inlet manifold the other goes between the manifold and engine when i touch this pipe i can hear air being sucked in any ideas what this pipe is?
cheers

kevh
Seat Leon Cupra 1.8T 03

 

[m0rk]

Could be a dodgey MAF, but the Y pipe sounds like a normal failure that will need replacing

 

[kevh]

Cheers
do you know what this pipe is called just to make it a bit easy to explain what i want when i go to stealers.

kevh
Seat Leon Cupra 1.8T 03