assume it's a 1.8, when replacing that 3 way work your way back to the "L" pipe that comes out of the oil filter housing, then to PCV valve, then work your way to the diverter valve, the metal pipes although hot act to condense crank gases and deposit coke on the wall ,which eventually clogs them completely. I get a rubber plug and pour drano crystals down into them (safety glasses ) pour a little water down them ,be careful they will literally get like 200 F. repeat until metal is visible, you will be surprised how much crap is in them ,btw, how many miles?