Ok here is the problem. As most of you already know this car is a great car if you have deep pockets. The problem that I am having this time is the damn CEL light. I went to Autozone and they pulled the codes for me. At first it said that there was a missfire. Went to a couple of different forums and came up with cleaning the EGR return valves. Pulled all that apart and they were so badly caked that I just figure that was the problem. Cleaned them all nice and pretty and the light went off. I was leaking some oil from bad valve cover gasket. Pulled one of the plugs out and there was oil on the plug itself and blowby. Then the light was blinking. So i took it to the machnic (who is very good) he changed the plugs (oem replacements) wires, cap and rotor. Did the engine flush and Amsoil oil change. Spent another $700. Well when i got the car it was idoling very low and wanted to stall. Plus there was some hesitation in the acceleration. Told him and he said lets see what happens with the light. Now I put shell v power in for the last two years. Now finding out that is one of the problems with the carbon deposits. The light is back on the engine is still running rough and I don't know what else to do. If anyone can help that would be great.