Hi

 

I have a 2015 ka 1.2 64000 miles

 

All yellow lights came on dash i changed both oxgen sensors as thats what i thought it required from the code. 

It worked perfectly for about 40miles

 

All lights back on again and also tyre pressure monitor comes up at the same time which seems strange 

 

code p0420

 

drives fine and tyre pressure fine. Anybody else had this problem 

 

Cheers

I had this code om my previous vehicle and could be a number of things. It could be a faulty or damaged 02 sensor or sensors, this includes the wiring for the 02 sensors, a faulty or underperforming catalytic converter, possible oil contamination of the catalytic converter, or a leak in the exhaust system before the catalytic converter causing the readings of both sensors to give a similar reading and setting the code.