Hopefully someone can answer my question? On my 2011 TT 2.0 tfsi quattro, the previous owner had it stage 2 revo tuned with a Cobra centre and rear section exhaust. After having work done on the haldex box, the garage informed me that my car would not pass the emissions test due to the removal of the CAT. 

I have the original centre section exhaust, just need to add the lambda sensors. 

My question is, will the original centre section fit back on, considering the remap, will i encounter any problems, error codes etc?

Thanks in advance

Gary 

 

You shouldn't encounter any fault codes as the map has already removed them regarding the cat if you see what I mean. If you do then a diagnostic check would need to be carried out or another remap.