I just replaced my injectors because of trouble code 093 and had deisel fuel in the oil on my 01 DMAX. Couldn't find anything cracked on the injectors or the fuel rails to cause the fuel to get in my oil, any thoughts on this? GM would not help me on this issue, out on the time, in on the mileage, 117,000. Truck runs good since the injectors were replaced, but I'm getting a trouble code 540 intake air heater A circuit. Not sure what I have done wrong if anything or what this code means, any advise?