2006 G35 Sedan.Service Engine Soon (check engine light) came on. Took it to local auto parts store, ran a free diagnostic. Gave me code P0420 which reads --- Catalyst System Efficiency Below Threshold (Bank 1) No other codes are with it. Just that. Randomly happened as I was driving home from work.So whats the difference between Bank 1 and Bank 2? Since my issue is only bank 1. Passenger side?? Does that help me find out what is causing this code of P0420 that I have??Honestly I haven‘t had any bad issues or symptoms. Gas mileage is still fine, no problems idling, going uphill, flooring it, or anything. Car doesn‘t smoke, any still runs like new. Just with this code on. I did notice that one day, it came on. went to bed and started it in the morning and it was off. But then came on again in a few days. Been on ever since. What does this code tell me? O2 sensors even though it doesn‘t throw a code that says o2 sensor or sensors is bad? The cat? Exhaust leaks? Thanks for the help!
Service Engine Soon Infiniti G35
Most of the times, it is a bad catalytic converter. Bank 1 just means it is the ban 1 cat that is bad if you have a dual system. If you only have 1 pipe, it is always called Bank 1
u need all new cats. 9 out of 10 p0420's need new catalytic converters. it is possible u have a bad pcm, bad o2's, exhaust leak, or bad wiring, but unlikely. it will not cause driveability problems because cat efficiency happens after your engine and in your exhaust. you cat is supposed to burn the hydrocarbons (fuel) that your engine did not burn completly. your car has a precat and postcat o2. your pcm watches for a change in oxygen content b4 (pre) and after (post) exhaust gas leaves the cat. if there is no change or not enough change, it assumes the catalyst is no longer burning excess fuel and is therefore polluting. if u care about the air u and everyone else breaths, buy new cats. ask for old parts back. sell old cats at recycler. they contain small amounts of precious metal. btw if u live in the usa and your car is less than 8yrs old and has less than 80,000mi the dealer should fix it for free. its a law. google it.
