Hey all -
So my '88 4WD is making some interesting sounds from the exhaust - and I'm not sure what it is, might be running rich? - I've checked all the things I could think of and replaced a bunch of them - plugs, rotors, wires, coil, checked timing, looked for vacuum leaks, a bunch of sensors, auxiliary air valve etc. Not getting any codes and have kinda run out of ideas.

It otherwise is running pretty well!

Please take a listen here: https://drive.google.com/file/d/1DXN...EitGSYO4j/view

Would love any ideas and thank you!