Random Misfire Code

Hi all, I have a 99 Tacoma access cab 3.4L V6 4x4 manual with about 245k miles it runs very smooth and I’ve had little issues with it.

However, yesterday when I was driving at highway speeds I would get the dreaded flashing check engine light, it would only come on going highway speeds and only for a couple of seconds, this happened only 3 times on about a 3 hour round trip.
When I got home I pulled the codes and I got

- P0300 (random/multiple misfire)
- P0301 (cylinder 1 misfire)
- P0304 (cylinder 4 misfire)

I was wondering if I should be diagnosing issues for the random misfire code or just focus on cylinders 1 and 4. I am just wondering if it’s throwing P0300 because I have 2 cylinders misfiring or if it is really a random misfire?
This is my first time posting here so if I left out any information please ask.
Thanks, Sam

 

Cylinders #1 and #4 fire off of the same coil. I would swap coils first and see if the problem follows the coil. If it does, replace that coil, no need to replace coils that are still operable. Use factory parts.

 

I have already done that and cleared the codes, I am just waiting for it to show back up, my concern is that it is intermittent and not a consistent issue.

 

I’m with glamisman it’s going to most likely be the coil pack. Since you have already moved it just set back and wait for it to pop its head back up.

When were the plug wires replaced last?

 

I’m not sure, they are the same ones that were on it when I bought the truck, however the wires don’t look burnt or frayed at all and seem to be fine.

 

So you already put a coil on it but no wires?

 

They don’t have to look bad to be faulty.