2004 Sentra 1.8L - Rough Idle

[Saga286]

Hello, I am trying to figure out what is wrong with my sisters car. It is extremely rough when idling. So far when we looked at it, the valve cover seal, and to spark plug tube seals needed to be replaced since there was oil everywhere. We changed those, so no more oil from what I can tell right now. We changed the ignition coils and the spark plugs and there is no change to the rough idle. This is my extent of my knowledge honestly. I am still trying to learn more. The car is showing multiple random misfirings code when scanned. While the car was running we took the clips off of each ignition coil one at a time to see if there any changes. The moment we removed either the 1st clip or the 2nd clip, the car would shut off almost immediately. Whenever we removed either one of the 3rd or 4th clip, the car would continue to run with no change or there was a very slight change, but it would not shut off. What could be causing this?

[veery]

FIRST - check for vacuum leaks. This is most common cause of random misfiring codes

Then:
Swap coils 1 & 2 for 3 & 4, and then test to see if it stalls when you pull the 1st or second clip. If so - coils bad (I know you changed them). If no change pull plugs and see if wet or not. If plugs from cylinders which aren't firing (no change when pulling clips) are not wet you have a fuel/injector issue.

This is a simplistic answer. If you have poor compression, good spark and fuel, you will still run rough.

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