P0420 2005 Nissan Maxima -

Question

What could it be the problem on my car?, it drives ok but i dont know what to do, is it expensive to fix?.

Answer 1

P0420 usually means the catalytic converter is bad (at least $800 for a new dealer catalytic converter ). This is caused by using low octane fuel which will damage the catalytic converter in the long run. I would do any intake flush and use 91 octane from Shell and a good fuel system cleaner. Small possibility it will work but I have seen it