I changed my timing belt over a year ago and 2 months after i ran into a vacuum leak that took quite a bit to find. i made the mistake of driving the car like that for a few months before really digging deep to find all the leaks. after fixing all the apparent leaks ( using a cigar to blow smoke in the system) i still have the rough idle, although not as rough as it was before. i went to autozone and cleared the codes waited for them to trigger again then pulled them and i got p0300,p0301,p0304,p0302,p0303,p0722. the biggest issue is that when i stop and the car down shifts to 1st gear the rpm drops really low and sometimes just causes the car to turn off!!!

 

you have a 1.8 or a 3.0 Might check your coil packs or spark plugs.

 

it is a 1.8t and would they all go out at the same time?

 

it could happen. But odds are its one going bad that is causing problems downstream. But its a fairly inexpensive part and u can diy swap in all of about 20 minutes.