The wires for cylinder #5 run back along the top of the engine to behind the left cam cover. Then down and to a big connector held together with a bolt in the center right under the power brake booster. From there it runs over the PCM connector between the brake booster and inner left fender. If it happens when putting it in gear, this rocks the engine slightly and may be moving the harness enough to cause an intermittant open or short.
Vislually inspect the harness along the engine and especially where it runs along the back driver's side of the engine. The bracket that holds the windshield wiper assembly in place has a sharp edge along with the area in the back of the head. The engine harness passes very close to these areas.
While the engine is running you can gently tug and shake on the harness from cyl 5 to connector and to the PCM and see if it causes the problem to occur. This may give you a starting point to check that are of the engine harness.
His: Blue w/Light Flint Born 02/05/03 (Wednesday)
6674 of 7838, Color sequence 102 of 327
1 of 111 Without Heated Seats
6 CD Changer in Trunk
Locking Lugs
Trunk Organizer
Real Oil Press Guage w/MM Face
Marauder Side Emblems
Rear Bumper Inserts
Nephews: Blue w/Light Flint
Born 02/05/03
6673 of 7838, 101 of 327 Blues 1 of 111 Without Heated Seats
Cars purchased 7 years apart, but are only 20 VIN numbers apart. Sequential units on the assembly line.
Hers: Black 300A w/Charcoal Born 06/25/02 (Tuesday)
2011 of 7838.
Locking Lugs
Trunk Organizer
Real Oil Press Guage w/MM Face
Factory Alarm
Marauder Side Emblems
Rear Bumper Inserts
#4 (Pound Rescue Marauder) 2003 DBP/Light Flint
120 of 328 DBP 1 of 217 with heated seats.
6705 of 7838 2003's
Built Friday 02-07-2003
Bought 09-10-2012
#5 2003 DBP/Light Flint
136 of 327 Blues 1 of 111 W/O Heated Seats
6741 of 7838 2003's
Built Tuesday 02-11-2003
Bought 05-06-14