Yup disconnected the negative cable last night drove around and CEL back on I'm 99% sure it's the 0420 code I'll keep updating till I get worked out. Now on that 0420 code (when I had access to that scanner) not sure if I already mentioned this after driving for awhile monitoring O2 sensors I noticed the rear O2 heater never turns off. Is this normal? I guess I was always under the impression once the car was good and hot and in closed loop the heaters weren't needed. Now the upstream O2 sensor will cut on and off.

 

I'd assume the rear heater remains on the whole time. Maybe it is cooler at the cat?

Watch the signal from the rear O2 sensor. I wouldn't worry about the heater part of the circuit.

 

Yup it's definitely the P0420 code. I wasn't putting a whole lot of stress on the idea of the heaters being an issue I just was under the assumption that the heaters were suppose to turn off at some point but that could just have been my misunderstanding of operation. I guess because I understood that there was suppose to be a temp rise across the cat of roughly 50 degrees in a correctly operating system due to chemical reaction. Unfortunately I don't have continued access to a data logging scanner so imma be taking educated guess at which part to replace next. The car has over 350,000 miles on it and I am going to be putting new pistons and new rings in it shortly due to the fact it has been burning a fair amount of oil (no visible signs of oil leaks, I've been good at the up keep on those). So I'll keep this thread updated as I continue through. I bought the car 4 years ago with the understanding that the cat had just been replace and the previous owner stated the repair technician claimed the light stayed in after the cat replacement because it was an after market part and the sensors didn't like it (just in general I've never liked that answer being a technician myself I feel that's a cop out). I've previously removed both O2 sensors and did the white vinegar over night cleaning issue is still there so again will be installing new pistons and rings I. The next few weeks and I'll do my best to keep updated for any changes.