Hello I had the PCM replaced at a shop then a month after that I started getting the codes P306 and P206. The shop was no help and couldn't really tell me what it was only that it may cost $1400. So started doing this myself. I've change all 6 fuel injectors, replaced ignition coil and fuel wiring harness and spark plug wires (I couldnt get the actual plugs out). The 306 code is gone, but the P206 remains. White smoke also comes from the exhaust. Hopefully it's not a head gasket. Any sugestions?