i was wondering if anyone has heard of any problems with carbon buildup on the intake manifold. on my 4th trip to the dealer, for a check engine light for a slow responding o2 senser, they said they found carbon buildup in the intake ports, and that a couple of them were blocked. my question is 1)if this were the case shouldn't the car have been running crappy, 2) isn't the gas injected directly into the cylinders on our cars so how does the carbon get into the intake past the intake valves, 3) has anyone else had similar problems?

 

i was told by an employee in the parts department that its a common problem on tl's