I finally have my car back with the hedmanns installed.
On the way home i had the ses-light coming on. is there any usual fault with installing headers that can cause the ses-light.
I don't know if disconnect the batt would help?

Thanks for the input

 

Check the codes.

First thing that comes to mind would be something to do with the O2 sensor.

 

Ok, we checked the codes and it is the O2-sensor.
Funny thing is, yesterday i drove 17 miles to work and had NO light. Later on the way to the dealer, the light showed up after about five miles.

On the way home I had the light after 20miles for about a half mile and then it went away.

Now I'm wondering if there is just a weak connection.
Or could it be that there was something in the headers (oil or something from the coating) that caused this reaction of the sensor. (at least they smelled kinda on the first few miles)

Well, we will see.