Scanned at Auto Zone. #4 coil pack and plug needs replacement

My 07 4runner has been hit and miss with running rough. Since yesterday it's been running rough no stop. Stopped by AutoZone they scanned it and scan says #4 coil pack and or spark plug. Yesterday I replaced the coil pack after putting on a new one 2 days ago. My Fixed scanner and Auto zones both said #4 coil pack and theirs also indicated spark plug bad. I bought a Bosch #672 plug from their. Replaced it and put back the new coil pack. Still running rough and now seems to not want to idle. Any thoughts. She has 285000 miles on her. My 4runner is almost mint and want to keep it

 

Maybe it's not the number four. I'd start the Runner and pull one plug wire at a time. You should be able to determine which is the issue.

 

Thanks I'll give that a try. I'm also wondering if they gave me the wrong plug....it is AutoZone

 

I don't know about the plug but if it's a plug or coil pack it should be easy to test. Please do come back and let us know what you find.

 

Stop buying new stuff. Don't even need to go to autozone.

Just disconnect the coil pack and see how the engine runs. If you take it off and runs even more like crap you know it was good. Find the one that the engine doesn't change how its running.

You sure you even replacing the correct cylinder pack?

 

Should be easy enough to look up.

 

Post the codes.