Volkswagen Jetta Decreased Power and Fuel Economy due to Carbon Buildup

The 2006-2016 Volkswagen Jetta uses FSI and TSI direct-injection engines. These engines have an intake system carbon buildup problem, which can cause power loss, OBD codes, a check engine light, and a rough idle. Possible multiple trouble codes.

The solution is to remove the intake manifold and clean the intake manifold's internal passages, the cylinder head intake ports, and the intake valves. This may need to be done in as few as 20,000 miles.