1995 Toyota Camry 2.2 L.
Repairs for this problem: plugs, and wires cap and rotor, valve cover gasket.
Question: After it warms up there is a lose of power and leaks oil from back of engine. If you let it cool you can drive for another 5 miles and does it again.

  Then it won't shift into high gear.  Does it sound like a catalytic converter or head gasket?

Answer: The loss of power under acceleration does sound like a plugged converter, or possibly loosing fuel pressure. But neither explains the oil leak. It may be that the head gasket is leaking oil, Toyota had a problem with that. But that would not explain the lack of power. It may be that your car has 2 problems. A plugged converter and a leaking head gasket since when the engine warms up the oil is thinner and can leak from a bad gasket easier. You will need to have a mechanic look at the oil leak and to diagnose the running problem. Removing the exhaust before the converter and running car to see if it is better is a good way to test it.

Hi, was wondering how much should I expect to pay to replace the rear main seal on mt 1999 toyota camry le. 4cyl.? While the transmission is out I"d like to reseal the front pump seal and all gaskets too.

Answer: This is  a pretty big job. The transmission has to be removed to change the transmission front pump seal and rear main seal. You be looking at anywhere from 7-10 hours labor depending on the shop. So multiply that by the dollars per hour they charge. The parts are fairly cheap, about $40.