Updating catalyst control center
If your car's check engine light is on, get that code read in case it's a P0420.
If your car has multiple trouble codes (DTC's), it's always a good idea to fix them in the order they come up on the code reader.
For example, if you have these codes - P0300, P0420, P0171, then you're going to want to tackle the P0300 Random Misfire code first (resolve it), and then tackle the P0420 code, etc.
Plus, if your check engine light is on for a P0420 code and you decide not to fix it, another more serious code could be triggered and you'd never know.
The MIL lights up whether you have one code or ten!
To start, we strongly recommend you seek the services of a professional mechanic/technician if you have any doubts as to whether you can perform the repair!
Also, be sure to follow proper diagnostic procedures to determine whether a part has failed.
The reality is there is still something wrong and your car needs attention in order to be in excellent running condition.
A poorly maintained car will run less efficiently, burn more gas, and cost you more money in the long run.
On inline engines such as 4 & 5 cylinder engines, there is only one bank.