Hi All,

I am in need of some help trying to figure out what going on with my 2008 S. It has the CEL on and the code I am reading is P129D. I can reset the code and it doesn't come on during my 18 mile drive to work. When I start the car again it comes on. It seems to have something to do with MAP sensor? I have ordered a bently manual to help with the trouble shooting on this. Any ideas? Thanks

 

Just an FYI on this issue. I took the car to a local repair shop in North Conway NH (Importech). They figured out it was the MAP sensor on the intake manifold. So far the car is running well with no more CEL. It also was determined that the famous carbon buildup issue is a pending issue that I will need to take care of soon since the car is at about 58K miles. The sensor was loaded up with carbon as well probably causing the issue in the 1st place. The repair shop used a scope and noticed the valve build up as I've seen mentioned before. Anyway, shes running great at the moment.