Brads

The engine light came on yesterday after driving for around half an hour. 

Hi I’m new to this group, but am looking for some advice. I have recently bought second hand japspeed sport cats. After getting them professionally fit my car has been jolting when trying to accelerate. The garage has said it’s due to the new cats as the r faulty. I have spoke to the seller and said the problem, however he says it is impossible for them to be causing this problem. Any help would be appreciated.