Coil Pack Question

[elemgee]

I have a 97 SVX and it recently started running rough. It showed a check engine light, and the code reader showed a "#5 cylinder misfire" (passenger side cylinder closest to the firewall), So I replaced the coil pack for the #5 cylinder and cleared the codes. It still ran rough and showed a check engine light, which turned out to be "#4 cylinder misfire".

The first check engine light only showed the one code (#5 cylinder). So I have two questions: why would the #4 cylinder go out right after I fixed the #5 cylinder, and should I just replace the remaining coil packs?

Thanks.

Larry

[Blacky]

First check to make sure you didn't disturb a connector or something when you changed number 5.
I usually confirm which one is misfiring before I start replacing things. If you pull a coil wire and it runs more rough, you have the wrong one. If it runs the same you've found the bad one.
You can also swap them around and see if the misfire follows. Plus it could be something else causing it like a bad spark plug or injector.
In 14 years with 3 different SVX, I only replaced 2 coil packs.