[SoCal LS-L]

The beginning of your post is a little confusing...... if you mean that the SVX that you reinstalled the cone filter on is having the problem...... then I would suspect that if you re-oiled the filter, oil may have shed from it and fouled the MAF vane. I suspect this because you said it happened shortly after you did this, and your symptoms are indicative of a possible MAF issue. Clean the MAF and see if that helps would be my first guess.

Second guess would be the crank angle sensors directly under the alternator, since you could have possibly accidentally nailed one when you did the alternator swap.