It's a 96, surprised I left that out. It's late, but I have a mind now to clean the plugs in the morning, along with the upstream O2, and replace the manifold donut which I suspect but have never...

Lean and rich at the same time? I can believe rich because my 2.5 is probably averaging 8mpg rather than a best of about 15. I performed an ignition service, installed new NTK oxygen sensors,...