Hi guys!

A little while ago, my car started doing some funny stuff.... loss of power, hard time starting etc. (2003 G35 Coupe with about 50,000 Miles)

I plugged the reader into it and it was throwing some errors.... Knock Sensor, camshaft sensor.

So I went to replace the knock sensor this weekend.... but when I opened up the intake I notice carbon build up on only half of the cylinders? Could this be the issue all along? Is that kind of build up normal? You can see a picture of it here:
http://www.sheltersix.com/images/photo.JPG

Any thought son if this is normal? if not, what could be the cause?

Thanks!
Dan