mixture

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...

what is a good way to know A/F mix? i know it can be seen by the color of spark plugs, but i am driving on LPG and i think it makes spark plugs looking white..meaning lean...of course when i am boosting i switch back to gasoline... is there a way to see a/f mix using vag com?

Those of you that use Viro-sol on your wheels/arches/etc. What strength mixture do you use? Do you use it neat? Given how dirty wheels can be neat seems like the best idea to me. James (Mis-spellings to assist future searchers: virisol, virusol, viri-sol, viru-sol, virosol)