Catalytic converter

[maoreilly]

I had the catalytic converter on my 2000 Subaru Forester replaced in August 2008. When the “check engine” light came back on two weeks later, the shop told me that it wasn’t working properly and they would replace it (no charge, under warranty). Three months later, I went to a different shop to replace the clutch and was told that the oxygen sensor had not been installed properly and that the converter was not the right one for my car (was not set to California emissions standards). So back to the first shop, and was told that the would replace the oxygen sensor but it was not under warranty. They did that, and a week later the light is back on and they finally agree to replace the catalytic converter. Two months later, and now the light is back on and the new shop tells me that the front catalytic converter gasket is leaking and that the catalytic converter is an aftermarket part that may not bave been checked before being installed. aaarrrrgggh! Do I go back to the first place AGAIN for a THIRD catalytic converter? How do I get this problem fixed so it stays fixed for more than a few months???