2000 Honda Civic VP
The engine light is on as well as the computer saying that 3 systems are not ready. Catalyst Monitor, Evaporative System Monitor, O2 Sensor Monitor. I am getting the diagnostic trouble code of P0135 which is O2 sensor heater circuit malfunction (bank 1 sensor 1). Is this likely to be a simple fix of replacing the O2 sensor or something more complicated?

 

A "not ready" code occurs because the ECU has been recently reset. The car must then be driven for about 20 minutes to clear it. During this time there is a not ready code, but the CEL will not be on. This is to prevent people from cheating on the smog test by resetting the ECU just before going in. If the BACK UP fuse is blown, the ECU will reset itself every time you turn the key off and thus there will always be not ready codes.

Check your fuse 15, that will kill power to the O2 sensors and the evap solenoid (as well as the alternator and speed sensor). On 1996 to 2000 models the wiring harness behind the engine is prone to rub on the intake manifold bracket and short out, a.k.a. the "fuse 15 problem."

If it's not that then check for a bad seal on the gas cap for the evap, check O2 sensor heater resistance and replace sensor if open circuit.

 

Found a crack on the manifold of the front catalytic converter. I am thinking that this may be the problem. It is all one piece with the cat so ~400 to replace.