Engine light came on after replacing the O/S/F headlamp bulb

[Backers]

Hi all

Audi A4 B8 3.0L diesel sline 2013

I recently replaced the O/S/F headlamp bulb by removing the airbox. when i restarted the car the  enging warning light came on and i cant figure out why. I removed the code and it was ok until i restarted the car the next morning when it came back on again .  There is an electrical connector under the airbox which i re attached and a small air tube/breather/vacuum pipe  running across the front of the engine which i also reconnected. Any suggestions would be welcome 

Thanks

[Steve Q]

I'd recommend a diagnostic check to see if any fault codes flag up. If you've removed the air box the only thing I can think you've dislodged is the maf sensor.