I recently replace my spark plugs & boots because my truck was running so rough and the service engine light came on. After changing them there was no change in how bad my truck was running. I took it to auto zone & they said coil #3 & #6 were bad So i replaced them. I started it up & it sounded great! The service engine light went out so I drove it around the block still great. The next day I started it & it was idling a little rough. I drove it a couple of miles & it started running really rough again and the service engine light came on again. HELP! Do all the coils need to be replaced?

 

You need to fill your info in so that it displays with each post, like mine , -top right corner.

That way we know what vehicle your talking about and further,- help you out.

Look above, -black bar, click on "User CP".

 

What was the code the second time?