Car is running rich, can't figure out why...

[HighMileage230000]

1989 Rivi-233k +++

Within the last 18 months I have replaced the plugs, wires, camshaft position sensor, crankshaft position sensor, idler pulley,water pump, ICM, and coil packs. The thing still runs rich as heck and the strange thing is-once in awhile it actually acts like it is leaning out. It has a cat on it still and there is no CEL or problems on the CRT. Fluid levels are all fine. This thing has got me stumped. Could it be the O2 sensor or something else?

It doesn't really run rough...it hesitates here and there but nothing too drastic, and once in awhile it idles roughly intermittently.

[discnik]

What leads you to believe it is running rich ?

You said no CEL.

[HighMileage230000]

ummm......the fact that it emits strong odors of unburned fuel from the tailpipe makes me think that it is running rich.....isn't that what cars do when they are running rich?!?!?

[maxwedge]

Many things can cause this, low engine vacuum, leaking injectors, excess fuel pressure, bad coolant temp sensor, bad o2 sensor, a full scan is one starting point. Check fuel pressure another.