P0303 + P0316: Cylinder 3 Three Misfire Detected

[SyberTiger]

Engine on my 2002 Ex with 4.6L has been running rough lately; most notable at idle or start from stop. Didn't get a CEL until yesterday. ForScan/Torque showed P0303 and P0316 engine codes thrown.

P0303: Cylinder 3 Three Misfire Detected
P0316: Misfire Detected on Startup

I took the coil pack and the spark plug from cylinder 3 and swapped them with cylinder 1. Reset the codes and checked for continuing rough engine and waited for code to be thrown again. Got new code logged this afternoon as P0301 + P0316 which is good news that the problem followed the coil pack and spark plug. Spark plugs only have 8K miles on them so I'm going with the coil pack as being the problem. They are the original coil packs with 164K miles on them so they are probably ready for a replacement.

Anyone have any luck with the generic 8x coil pack sets sold on eBay for $30 - $40? I see that a number of folks said to avoid the cheap coil packs on eBay but was curious if any of you have actual experience with them. It looks like the cheapest set of OEM Motorcraft coil packs is on Amazon for $192.

 

[Joe in NY]

Really only need to do one at a time. I've done 3 in 5 years from 60k to 105k miles.

Want good for cheap? Go to advance auto online, pick out the BWD non p series coil and use RMN25 plus any speedperks. Made in Poland, high quality, and pretty cheap considering.