No change with the air filter element removed. Looked at the air filter with a flashlight behind it, and the filter is plenty clean. Can see light through it all the way around.

I did notice while working the throttle from the engine bay with the filter in place, that I can hear a low sucking sound from the airbox. Similar to when the secondaries open on a 4 barrel carb when you punch it. I had a buddy stop by yesterday, who has owned several Mistubishis and he seems to think I'm dealing with a sensor issue (specifically the MAF or the TPS, or a vacuum problem. His opinion is the timing is on, and fuel is not an issue.

I'm going to pull up the vacuum diagrams in the FSM and make sure everything is good there. And see what tests can be done on the TPS and MAF. Might be able to borrow some working sensors from the AZ crew to troubleshoot with.

One thing to note is while checking out the MAF, if I gently shake it, I can hear a rattling noise like a loose part within the little black box above the connection. Also, the engine doesn't run any different with the MAF plugged in, or unplugged. Curious.

Also, I noticed that someone put RTV sealer at the connection for the TPS., so it has been messed with at some point.