Is there anywhere that has what a specific "flag/s" do or at least where to read up on this? I've got 15 hrs wrapped up into why I couldn't read my 4288/$AO with my scanner and come to find out it was because of a "EST Monitor Error (Err 42, X=Enable)" flag was set. Unset it, burned burned it and now I'm in business. Hmmmm...now the silly thing is I have another 4288 with the same $AO program on it but with different perameters on it for a bigger motor/5.9L and it has this Err 42 set but I can scan it every time.

Now the crazy thing is I took the same $AO eprom and put it to the hex editor and changed the ID to $42 , burned it to a chip and installed it in a 7747 and it runs the same(I dont get the lovely limp home strobe effect flash's) but it dont care if the 42 flag is set or not , it's still not gonna let the scanner read it.......I get the dreaded " vehicle not responding" error. GRRRRRR. It all seems to go around these flags but still to new to know. Just wondering if there was a method to the setting of these flags? Thanks in advance for any info.

 

Simply changing the ID to $42 is not going to help as all the other tables are in different addresses or locations on the chip.
Go to the DIY-EFI webpage and get the ATKX calibration for the 7747. It is a stock HO 4.3 calibration for an Astro/Safari mini van. It is a good starting point for your 6 cylinder. Next get the ASDU, that is a 350/Automatic- Truck/Van/Suburban file. Would work as a great starting point for your 360. Assuming the 360/350 Injectors/Stock 12 PSI pressure-Bump the BPWC up from about 135 to around 140 and go to town. Then make sure that you are using it in conjunction with a 7747/$42 .ECU file!