My car is a 2002 Civic. Recently, the engine light turned on. I went to a garage to replace the rear sensor, but the engine light still come up after a couple of days driving. The technician there said I may need to replace the front sensor as well but that is a rare case and not cheap. Any suggestions?

 

What is the code? Do you know what was replaced? I don't think there is such a thing as a rear sensor.

 

I did not ask about the code. The technician replaced a sensor that control the emissions between the rear tires.

 

I asked the code was 1456, any comment?

 

Either a fuel filler cap isn't sealing or a possible leak in the filler neck, could easily be the problem at hand.

 

Each time after I filled up the gas, I tightened the cap carefully by hearing at least three clicks.
Can the gasket affect it? The technician mentioned that the gasket starts to loose.

 

There's a good video out there on the P1456 code, and the fuel filler neck seal issue.

 

On a 2002 at this point you might want to look at the vent valve solenoid.