I got my SPT for $75 used. Then I made a CAI from plastic conduit pipe and a rubber plumbing adapter for $13 from the Depot.
The filler neck cover is in the wheel well. Held in with a couple rusty bolts. If you want to see something scary, take that cover off.
Might be worth taking a look under your gas filler spout cover.
I had some bad gas order with my 99obs and it turned out that the filler neck was rusted through. (common issue I was unaware of)
I pulled off the cover to discover massive amounts of dirt/sand packed aroung the tube.
-On your...