carbon build up

Hi all, I was wondering if anyone could provide some feedback or share some experiences with a similar issue. We recently experienced an issue with our car with relative low kms (130k). Feedback from the supplier can be seen on the attached. Maintenance has been up kept and it is a 40km to...

I have a 2007 Mazda CX7 with 144k on it. I have had more issues than I can count and have usually been able to fix them until this latest issue... Car has been driving very poor for the past 2-3 months but haven't had a chance to spend time on it (figured it needed a tune up). Been getting two...