I have a 1996 Chevy van 5.7, its very hard to start, it turns over fine but doesn't want to start. Eventually if you keep cranking it will start. I put a code reader on it today and it gave me a (dtc P0155 which is oxygen sensor heater malfunction bank 2 sensor 1). I just didn't think the o2 sensor came into play until the EGT was up to 600 degrees F. Could this possibly be the cause of hard starting. Thanks in advance!