I am sure this has been covered but I did not find answers to my specific questions. I have been reading about the Evotech ECU upgrade. I currently have a 2003 MCS with a 15% pulley and a CAI. Would the ECU upgrade be the next best choice? I do not want to change the stock exhaust sound. IMHO a loud 4 cylinder engine is not music to my ears.

So, what stage Evotech ECU would I want and what differences will I notice? Will I notice a big power difference as I did with the pulley upgrade? What other changes will occur as far as drivability goes?

Thanks,
k