mazda b2200 1989 ,I have oil in my airfilter coming into it from the pcv valve, seems like the valve is ok. my precat is geting real hot, won't run under a load can only go about 35mph up small hills. thought iwould replace the manifold and cat with a pace setter header to get this to run. any advise!

 

Sounds like a condition of excess "blow by". Blow by is a product of cumbustion when compression is escaping by the piston rings then it pressurizes the crankcase. It is normal to have a small bit of blow by...this is what the PCV valve usually takes care of. When it gets excessive you will see a good amount of oil vapors while running and it builds up in the air cleaner housing. The engine is producing more blow by than it can handle. I would start to think about an engine re build soon...in my opinion.