[Bladecutter]

I would recommend trying two things before blaming it on an air leak, and will help determine if its a coil pack issue, or an oxygen sensor issue, or even possibly a clogged fuel injector issue, as 30k miles on a 97 might have lead to clogged injectors from lack of use.

Start with the most simple thing:

Dump a bottle of Chevron Techron Fuel System Cleaner in with your next full tank of gas. That might help clear out some minor fuel clogging issues.

Next up is to remove the coil packs from each cylinder, and swap them from the left bank to the right bank. If the problem is with the coil packs, it will follow them to the other bank.

After that, I would swap the oxygen sensors from the left exhaust to the right exhaust. If the problem is with the oxygen sensors, then it will follow them.

I recommend doing these one step at a time, and wait a week before doing the next item. If you are good with working on cars, you can do all of this yourself, because its all easy stuff to do.

BC.