I recently lost a heap of power in my 01 V6 Camry. My Scan Tool won't hook up, it says it has a Link Error. So I'll do this the old fashion way. I went to two Exhaust Shops and they both won't give a rough estimate to fix / replace the the Cat(s). Talking about that I'm assuming because it's a V6 it has two O2 Sensors??? How do I determine which Cat is stuffed or O2 Sensor??? I see on U-Tube guys trying to 'clean' the Cats. Is that even possible???