Hey guys I have an update on the P0128 and P0420 problem I was having. As it turns out like you guys said the thermostat was stuck open thus causing the engine to not reach normal operating temperature which actually caused the P0420 code.

The way I found out was by looking at the live data from my 02 sensors. The pre cat o2 readings and the post cat readings were very similar with the bad thermostat but after I replaced the thermostat the post cat o2 sensor reading changed dramatically. The wave

form was almost flat which would indicate the Cat was doing its job by reducing emissions. I am honestly shocked at how many problems you can get from your engine not reaching the correct operating temperature. I really appreciate you guys helping me solve

this problem.

P.S. I tried to upload a screenshot of my live data so you guys can see for yourselves but was unable to because I exceeded the size limit by 25kb. I will see if I can shrink the image and try to post it later. Once again thanks for your help!!