Ok, 20,000 mile ago I had a private mechanic do my timing belt and tune up. 5k miles later the truck threws codes galore and started pinging. I then went to toyota to find that the timing belt had gotten loose and was wreaking havock because of a loose pully. They fixed the issue as I understood but there was some damage to a pully, they said it would work but it may in the future need to be replaced if this happened again. I want to figure out which pully (If I knew the pullys I could figure out which) needs to be replaced I think. So that I can ask if they have the part before I go and find out they don't after sitting in that great old waiting area for an hour 
edit: After talking to several parts department, does the idler pully sound right? I'm trying to figure out all the pullys connecting to the timing belt.

edit: After talking to several parts department, does the idler pully sound right? I'm trying to figure out all the pullys connecting to the timing belt.
Registered User
You have an idler pulley near the center below the cam pulleys and there's also a tensioner pulley located at the bottom left corner of the engine (looking at it from front). I'm attaching a pic.
no one knows the pullys on the 3.4? I hardly believe that.