What would cause an oil leak at the rear of my 2003 Chevy S-10 With 2.2L eng.?

the oil pressure sender unit will be in that area so check that it has not failed or leaking from around the thread
another place of leakage is the rear edge of the rocker cover where the gasket has failed or not been fitted properly or loose screws for the cover

Virtually none. If you have significant crankshaft end play, and you are not leaking oil, don't worry about it. If you are leaking oil from the rear main seal or from the pulley seal, consider rebuilding or replacing your engine before it seizes.
Recommendation: DRIVE IT 'TIL IT DIES. Replacement engines for your vehicle are abundant and not particularly expensive.

Trouble Code: P0420

Catalyst System Low Efficiency

Possible Causes:


Air leaks at the exhaust manifold or in the exhaust pipesBase engine problems (i.e., high engine oil or coolant usage)Catalytic converter is damaged, contaminated or has failedContinuous engine misfire conditions, or weak or low coil outputFront HO2S or rear HO2S is contaminated with fuel or moistureRear HO2S is loose in the mounting hole (check it for a leak)Front HO2S older (aged) than the rear HO2S (HO2S-12 is lazy)

Dear,
Here are the parts that it must be checked:
Inspect Ball joints
Inspect Battery
Inspect Brake system
Inspect Brakes, front
Inspect Brakes, rear
Replace Cabin Air Filter
Inspect Cooling system
Inspect Drive belt(s)
Inspect Drive shaft
Inspect for leaks Engine
Change Engine oil
Adjust Headlights
Lubricate Hinges, locks & latches
Check operation Lights & accessories
Replace Oil filter
Inspect Power steering
Inspect Seat belts
Inspect Steering linkage
Inspect Throttle linkage
Inspect Windshield wipers & washer
Regards, Eng. Ghassan Alasmar

as long as it doesn't get on the brakes you're ok

Overfilled is not good but it would have to be very high to cause leak,There are numerous places in rear of engine that could be leaking.could be leaking from rear of intake,the oilpump drive o ring,but most likly leaking from rear main seal that seals at the rear of the crankshaft and the transmission will need to come out to access this seal. you will need to have the oil leak diagnosed to locate the exact spot.

this truck is equipped with an aluminum oil pan you could have 1 or several things going on... a stripped drain plug which is causing it to leak or it may be a leaking front seal or a rear main seal. If it is a front seal it is not to labor intensive. But if it is a rear main seal leaking it will require the transmission to be removed since the seal is a 1 piece rear main

you will have to replace its oil seal

Make sure your valve cover is tight. They are known to come loose. Ckeck oil filter tightness and be sure when you change oil the old gasket of filter does not stick to bkock.This will cause an improper seal.

CHECK THE OIL PUMP SUMP TUBE O-RING. THEY COLLAPSE CAUSING THE OIL PUMP TO PULL AIR INSTEAD OF OIL. TO VERIFY OVER FILL ENGINE OIL AND CHECK ENGINE OIL PRESSURE. THIS IS A COMMON PROBLEM ON ALL NEWER GM V-8 ENGINES : 4.8 5.3 5.7 6.0