I bought a new Fabspeed exhaust with hi flow cats 21 months and 14k miles ago. The cats are throwing an efficiency code. My shop called Fabspeed and they suggested I purchase spacers from them to limit the flow and prevent the codes. 1st all I am not looking for a Band-Aid and my shop tells me it is illegal here in Ga. I've spoken to Fabspeed twice over the past 3 days and all they tell me is a customer rep will call me back. No call back! I think they need to stand behind their product. If I had know the cats were only good for 2 years I would have bought another brand. Has anyone else had a similar problem? Thanks