EGT readings really depend on placement of the probe... so while the rule of thumb, 1600*/900* is generally accepted... it will vary from car to car of course. like, 7mGTE's are not supposed to get above 1500*, or about 850C, but, on a DSM, you could get up to 1600* or 900C... so yea it will vary. also the efficiency of the combustion chamber will also affect how much heat comes out the exhaust too.

Maybe i was thinkin of paxtons that have the oil resivoir.

anyhow, afterburn will cause too high of an EGT to be read, ive seen it happen before. its happend to fellow DSM'ers. they mistook the readings to mean too lean, and they added fuel and only made it hotter... so a few of us said, try leaning it out and everyone freaked... but lo behold, his EGT's cooled off.