COP and Plug Replacement, correct parts recommendations?

[Martin Rester]

07 Expy with 154000 miles, returning from trip to SC towing 06 wrangler. Traveling back to Texas from SC and after about 500 miles started loosing power violent shaking and check engine light. Had no power issues on trip out or until half way back to Texas. I stopped at an auto zone and had check engine light examined for code. Showed error code PO301 and PO300. Showed misfire Cyl 1 and Random.
As recommendation was replace COP. Only replaced on Cyl 1 at this time. Cleared check engine light and seemed to be fine.

During the rest of the trip still had a loss of power but no check engine light until 30 miles from home. Just happened to pass another auto zone and had check engine light analyzed again and same code PO301.

The plugs and COPs were replaced about about 25K ago. Replaces COP with Summit Racing brand (don't know specific model #) and plugs with Motorcraft SP-515 plugs. Engine ran fine and strong until now.

Now that i made it home was going to replace both Plugs and COPs again but my question is what COPs and plugs should they be replaced with as searching there are so many different one offered not sure what would be best for replacement. I have seen COPs, all 8 for under $100 and upto $400 a set. Hesitate to go with the cheep ones on Amazon.

Any recommendations would be greatly appreciated.

BTW very happy overall with this vehicle. Strong engine and runs great.

 

[Trainmaster]

Replace the #1 coil with a Motorcraft coil and leave the rest alone. Replace the plugs with OEM Motorcraft. Don't open a can of worms by replacing all the coils with cheap Chinese imports. Most of the original coils last for ever and there's no need to change a good coil.

Also, check your harness connector. A longshot could be a bad injector, but it's more likely that those Chinese coils were garbage. In my experience, most are.

 

[Martin Rester]

Yes, I will start with just replacing the plugs. As this is not my daily driver it will be next weekend before I get the plugs replaced. Thanks for your feedback.

 

[inmanlanier]

I agree with Trainmaster - since you used Motorcraft plugs only 25K miles ago - likely they are not the issue. Try the coil first.