Hello - I've been on the Yukon Tahoe forum for a few years but just found this forum as well... Having issues with my 2003 Yukon Denali - codes indicated bad injector circuit. We replaced a shorted coil, checked the spark plugs (all good), but it's still running terribly, really low power, blinking engine light, etc. How do we find the faulty fuel injector and replace it (there are 8 right?)? Thanks so much. 