1992 dodge spirit is leaking oil from under the distributor cap is there a seal under there and is it easy to change.

O-ring where? The drain plug? Distributor shaft? Or do you mean oil seal?
Geo oil drain plug specifies a compressible copper ring washer I think? Need to clean the surfaces well, and torque to spec. My own plug's seal is not perfect, but only a drop here and there usually. Autozone or NAPA can supply you a new plug and washer if needed.

probably needs the catylitic convertor replaced

Remove Bolts Drop Pan, Clean all serfaces, Apply Gasket sealer /Gasket replace bolts tighten to 23 IN pounds/ Add Recommended Oil,
Run to Check for Leaks, Probably 1 hour will show any leaks if not done Properly

You don't say what engine it has. The 4-cyl was a better than the V6 for oil leaks.

The V6 had oil leaks from

-rear bank cam cover gasket

-distributor o-ring seal

-oil filter bracket o-ring seal

-crankshaft nose oil seal (less common)

-rear main bearing oil seal (expensive, just leave it)

The 4 cyl leaked oil from

-distributor o-ring seal

-camshaft cover gasket

-rear main bearing seal (expensive, leave it)

there are usuallu clips, maybe tap light but firm with rubber hammere or knife handle wrapped in washcloth

ENGINE MISSING CAN BE WEAK COIL.BAD PLUGS AND WIRES.REPLACE DISTRIBUTOR CAP AND ROTOR.FUEL FILTER STOPPED UP ALSO FUEL INJECTORS CLOGGED UP CAUSES MISSING.CHECK UNDERNEATH CAR WHILE IDLING.IF YOU LOSING A LOT OF OIL.FRONT CRANKSHAFT SEAL OR REAR MAIN SEAL LEAKING OIL.LEAKING VALVE COVERS.DO A COMPRESSION TEST.AND CHECK CONDITIONS OF SPARK PLUGS.IF PLUGS SOAKED IN OIL.VALVE GUIDES + SEAL LEAKING OIL IN COMBUSTION CHAMBER.

Check around the distributor cap. Commonly drips from around the base of the cap and onto the manifold, causing smoke and a stink.

Also seen it leak around the oil cooler at the base of the oil filter. You will need to remove the air filter housing to get at this area, but not too hard.

change the oil ring inside the distrbutor and change a new one

Clean all the area and check again; maybe the seal need one new adjust or the oil pan cap too.

Tell us news.

Is it leaking arond it? Replace oring seal. Is it leaking from where the cap seals the the distributor? Replace the distributor.