If someone has this carbon build up problem and either can scope the car themselves or can ask their dealer what the codes that were thrown (obviously the carbon buildup can be difficult to diagnose), I would appreciate it and I think a lot of people would too. A few observations:
Is this a known problem? This engine has been around a while in Europe....
I dont see how this could be caused by EGR or emissions system, though maybe backpressure from a clogged SCR system could do something like this. Especially in view of CT_335D's post indicating his was caused by a bad injector which dumped too much fuel into the cylinders.
I have over 82,000 mostly highway miles on my 2009 and have noticed no loss of power. Have not had it worked on for any issues other than the normal scheduled oil changes when it was under warranty.
I do not drive my car hard. A lot of the highway miles were around 80 mph. I have one speeding ticket when I was going 85 in a 65 zone. The car has never been above around 126 mph (Hwy 1 outside of Sant Cruz, the Japanese car I was chasing had some nasty smell coming out of it, I think the engine was about to explode.
I even still have the original brake pads because I go easy on it, though I think they should be checked.
I do have a SES light on a lot, but it seems to be affected by whether I have filled up my tank recently, so I think it is probably just a defective fuel cap or something, though now I am worried.
I guess I have to hook up to the OBD system and see if I see anything.