87pathy5spd

So I few weeks ago I started getting the hesitation/bogging like it has a bad cat. Some power loss but not too bad. I filled her up the other day but used mid grade instead of the regular stuff. It greatly decreased the hesitation and bogging. Could this be something besides the cat? I rarely have the car over 3500 RPMS. It seems to be effected mostly between 2500 and 3000 rmp. I assumed I didn't have significant power loss because I belive the head studs or whatever are cracked, haven't looked but sounds like a big exhaust leak from the engine bay.

Thank you for the replys. I played with the search function and found alot of useful information.

Hello everyone, I am Troy. Currently driving/working on 86.5 xe 4x4 5 speed. I love the thing so far. Not too much rust at all, the frame has been ryno lined by previous owner. What are some ideas for my ride? I want to lift it some, but am having issues finding ga proper kit. Has anyone ever swapped a turbo motor from a 300? Thanks and I look forward to your replies!!! Also, I need interior dome lights, they seem to be hard to come by. Especially the one in the front.