If you have a severe vacuum leak, then your symptoms fit.
the leak could be anywhere, but I'd pay special attention to any of the areas involved with the work you just had done.

As a test, unplug the hose that runs from the manifold to the valve on the driver's side fender ( that is the canister purge valve ).
If it makes a big difference, then maybe you don't have a vacuum leak.

As another test, unplug the MAF/IAT sensor in the CAI, see what that does.