First off replaced passenger side head (2 spark plugs blew out) Cassettes and whole demo. Running ok bout a month, now p0351 appears: so far what I've done changed plugs motor craft, wires & coil 12.3 ohms cross all 3 AutoZone, new harness for coil clip was broken, new resistor (small black 1 that attached to coil)CEL still on 2 days later,✔over everything no spark cy 1&5 took and exchanged for another 12.89 all 3 hooked up ran like