I just had my timing belt changed on my 02. The car idled and ran fine for about 150 miles. Then the other day I ran it with the A/C on and it idles rough and has a CEL. Acceleration and driving is fine. Have to shift to neutral at stop lights. Could the belt have possibly slipped or is it unrelated?

 

Sounds like your timing belt is off a few teeth. The belt has 200+ notches for the teeth of the belt and they need to line up. The main (lower) pulley and the two top (cam) pulleys have marks on them. If you want to check them yourself, it takes about an hour.
Let me know and I will be happy to provide the steps.
Just did mine!
Tim

 

I ended up taking it to my mechanic. He said one side is misfiring completely and he's 99% sure it's the belt and offered to re do it at a reasonable price.

 

Good for you!

 

Yeah. My biggest concern is driving it.. he can't get to it till next week and I'm just going to park it till I go to his shop

 

Did you scan the DTC?
Find out the trouble code?

 

Trouble code is misfiring. Mechanics told me they're all on one side, and he's pretty sure timing is off.

 

I didn't realize this was such a complicated / expensive job on this car or I probably never would've bought it. And every 60k?! It's at 180k so I'm guessing something else major will break and I'll get rid of it before it has to be done again..

 

First off, I had 225k before I replaced mine. 60k is ultra-conservative.
You can check your timing marks but it will take ~ an hour and a half.
The outer belt removes easily with the tension pulley. Get that out of the way first.
Then remove the plastic covers allowing you to see the bottom pulley and the two top ones for the cams. Those three have marks and a notch to line it up. Move the bottom pulley to line up with the mark at about 2 o'clock and then check the two top ones.
That will let you know whether or not you are off. If it is more than 2 belt notches, it is recommended to realign it. Hope this helps.

 

You are both lucky, and foolish.

60k is the manufacturers requirement to keep your warranty. Foolishly choosing to go more than that and you risk engine damage and voiding your warranty.