After googling it is determined
Code P0420 ( Catalytic converter effeciency below threshold)
Trouble code P0500 means: Vehicle Speed Sensor A
Code 45 on a Honda Civic means the car is not getting proper fuel flow. All the major fuel components should be checked such as the map sensor, oxygen sensor, and fuel pump.
To fix a ratio on a 2000 Honda Civic transmission, follow the procedure stipulated in the users manual.
To fix a P0420 code on a 2005 Honda Odyssey, start by inspecting the catalytic converter for damage or clogging, as this code often indicates inefficient performance. Check the oxygen sensors for proper function, ensuring they're not faulty or misreading the exhaust gases. Additionally, examine the exhaust system for leaks that could affect readings. If necessary, replace the faulty components, and then reset the engine light and perform a test drive to ensure the code does not return.
you stick some plastic explosives on it and run
You will need to change the brakes and rotors on the Honda Civic to see if that fixes them. If not, take the car to a mechanic and have them fix the problem.
2004 Honda civic not giving good gas mpg
P0420 = Catalyst System Efficiency Below Threshold Bank 1.Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic converter needs to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first.
it cant be fixed just tightend your gas cap harder
DTC P0420 = Catalyst System Efficiency Below Threshold (Bank 1)You can drive it but it would be wise to have the vehicle checked out as soon as possible. Putting this off could cost you more in the long run. If you have other codes preceding code P0420 fix them in order as they come up before you attempt to fix P0420.
Replace the catalytic converterReplace the catalytic converter
Catalytic converter failure. Replace the catalytic converter.