Engine Mangement Light after Lambda Sensor Change

[ianfletcher]

Just changed the Lambda sensor on the manifold due to poor fuel economy, hesitation and the occasional misfire.
Problem is though after i finished i disconnected the battery for half an hour to reset the ecu and then i went for a little drive to test it which went well until i got back and turned the engine off which is when it happened!
I thought i would just try it again to make sure it started okay and the eml decided to show its face. Now i don't know why this has happened because the light wasnt even on with the old sensor.
The new sensor is a Fuel Parts LB1339 which is listed as compatible with a 1.7 puma.

Anyone have any ideas as to what the problem could be? :?

 

[ianfletcher]

Would the light need resetting with a code reader or would it eventually come back on again?

 

[red]

Is it the right sensor? The later Puma had 2 and I'm not sure wha the effect would be of wiring a post<->pre cat sensor.

 

[pumapilot]

My way to reset ECU, my EML light comes on every 100 miles or so, disconnect battery as you have done for 30 minutes, reconnect, start car and let it idle for 5-10 minutes, this resets the ECU's idle values, then take car for a 10 to 20 mile drive, so the ECU can adapt to your driving style.

My EML light comes on because the rear sensor on my Milltek sports cat sends out the odd spike or bad signal occasionally, if you reset the ECU and the EML come on again then i suggest you get it diagnostically checked, as for the sensor, was it a OEM Ford part or a cheaper aftermarket item? if aftermarket item then that may be your problem