I won't argue that with you Jerry. But a 2 speed idle test isn't really a true emission test. Years back when we first got our Dyno and testing equipment I did a Pre and post cat test at idle and 2500. The numbers were close, so close i would of just failed a test with no cat at all.

You would have to have some really issues to fail a 2 speed idle test.

In my experiance those cheap cats just don't work. There is a reason why an OEM cat is closer to $1000 an last almost the life of a vehicle unless murdered by poor tune of engines ie. misfires, oil burning,driving around with a bad O2.