Maybe you dislodged the plug/socket for the MAF sensor. this is the sensor inside the intake pipe, just after the air filter.
think thats ok also when people fit these filters what do they do with the pipe comeing from the airbox that goes to the front of engine it just sits spare now? cant remember what they call it now...thx
 
This pipe is for the aux air pump, it's to do with the immisions on cold start/fast idol. You can get a mini filter to go on it or make one out of sponge.

Don't just leave it open though as you don't want dead flys and other shite getting into your engine.
 
The traction control light comes on as a warning that you have pushed the button to disable it. Other than that it can be a faulty ABS sensor, the ABS sensors tell the car if wheels are spinning or not.