'02 XG350L timing belt problems

I recently had my timing belt, driving belts(serpentine belts?), and plenium gasket replaced. Afterwards my engine was louder and making a kind of rattling sound like when you really press on the gas pedal but this was at idle. My idle gauge wasn't fluctuating but the noise was there and you could feel it on the steering wheel and brake pedal. I had the shop take a look at it again and they said 1 tooth on the timing belt was not properly in place and was the cause of the problem. But it's still there. Would a timing belt cause this problem if not done properly? Or would the driving belts(serpentine belts?) cause the problem? Since I didn't buy the car brand new, I don't know exactly how it should sound or feel, but I doubt louder is better. Any help would greatly be appreciated

 

get them to properly align the tooths on the belt

 

If the noise wasn't there prior to the repairs, take it back and have them
check it again. If they want you to pay for the repairs, you can ask here
as to whether the repairs they wish to charge you for seem reasonable.
Also make it clear that if you pay for the repair, you expect the noise to
be gone. This seems like a fair deal. They're telling you the noise was
caused by something other than their repairs. If their proposed remedy
doesn't fix the noise, that reopens the case that their repairs created
the noise.

I've heard of some cases of the variable intake plate retaining screws
coming loose and allowing the plates to come off and rattle in the plenum.
(I've only seen this once, and it was on a 3.5 Santa Fe.) If this is
what's going on, it's pretty serious. The screws can get into the engine
and cause severe engine damage. Why was the plenum gasket replaced in the
first place?