engine check light pops up after covering 1 kilometre, why?

 

There is not enough information in your question to provide a good answer. (year, make model, etc.)

One common cause for "after the first mile" CEL or driveability problems are O2 sensor(s) that are not working correctly. The computer does not use them for the first couple of minutes/miles after startup until things get up to temperature. Then the computer switches over to using the sensors, and things begin to get out of spec (typically fuel trim values) and getting out of spec causes the computer to throw CEL codes.

 

Before you replace anything, check for any trouble codes. Even if the CEL is not on as there may be codes stored. Post what you find. And like jordan96xj said post the year, make, model, etc.).

 

Yup, agree with the others here. The devil is in the details.

1. Post year/engine

2. List the EXACT codes (not just a description). You will need a code reader or scan tool to do this (for years 96 and newer)

3. List any symptoms that you are experiencing.