1.) Idler pulley adjustment. I saw a photo of this pulley that shows an adjustment pin(eccentrically offset)that cannot be seen from the face, only from the back once its remioved, that acts(I presume) as an adjustment so you can put more tension on our belts.

is this type of pulley the rule with regards to our cars,so I will be able to know before having to take this pulley off.

or is this only select cars, and its a longshot that my 2.8L has this kind of pulley.

then the question comes.... how do I remove this pulley properly so I don't damage it and then put it back on by realigning that pin
into another spot.(for more tension)..

2.) The traction control light is staying on a lot of the time(but not always... Where is this control unit located and how big is it, etc. I want to check this thing out to see if its been water damaged>