Pulled codes on '93 5.0 and got 81,82,85,84. It cycled back and displayed the same codes again (as it should). Then, I got the 10 seperator code and the continuous memory codes came up. I pulled a 33 (EGR) and 66 (MAF). It cycled back and displayed the 33 again (as it should) but the 66 didn't appear the second time. Why didn't the 66 appear the second time? And yes, I waited long enough. A full 10 minutes after the second 33 code.