Having trouble with P1457 Evap System. Went through troubleshooting flowchart. Got the point that it suggest to replace ECU. Trying a new ECU and it will turn over but not start. Put original ECU back in and starts right up. Does the new ECU need to be programmed for Immobilizer for a 98 Civic EX? Any help would be greatly appreciated.

 

No

 

Car does not have an immobilizer. Likely your new ECU is bad.

For that evap code, check the wire colors on all the sensor plugs under the hood. The various 2- and 3-wire plugs are mechanically the same, they can be plugged into the wrong things.

 

Thanks for the replies. The ECU that I got was used but supposedly "good" but the seller had no way to confirm. I have another one on the way. Very glad to hear it will not need any special programming. On the P1457, the code had just popped-up for no apparent reason. I did not swap or change out anything in the system or mess with the wiring or sensors. I have read in a few posts that a bad solenoid could burn out the driver transistor in the ECU that controls the solenoids in the Evap circuit. All the troubleshooting from the service manual confirmed that the wiring was OK and that the solenoids are working and got to the point in the flow chart as the next step is to replace ECU. I hope that there is not an underlying issue that will also effect the replacement ECU. Any other thoughts and comments, please keep them coming. I can use all the help possible!