Need Help with Intermittent Misfire Issues P030X on 2010 4unner and P0351-P0356

Hi everyone,

I'm reaching out for some advice. I’ve been having ongoing issues with my 2010 4Runner Limited 2WD (258,xxx miles). For the past couple of months, I've been dealing with intermittent random multiple misfires (P0300-P0306) and ignition coil primary control circuit open codes (P0351-P0356). It was running fine for a while, but now it’s almost completely inoperable.

Here’s what I’ve done so far:

• Replaced the MAF sensor
• Cleaned the throttle body and air filter system
• Replaced coil packs with TRQ in 2022, along with new spark plugs

After experiencing these issues, I took it to a local shop that specializes in imports. They suggested the aftermarket coil packs might be the problem and recommended switching to OEM Denso coil packs. The shop replaced two of the aftermarket coils with used Toyota-specific ones to test this theory. The vehicle seemed to run better, so I replaced the remaining four with new OEM Denso coil packs.

Initially, the 4Runner ran fine for about 150 miles, but then I felt a misfire again, and the check engine and traction control lights came back on. This time, I got 13 codes indicating random multiple misfires and all coil packs open. I replaced the two used coils with new Denso ones, but now the 4Runner struggles to stay running. It idles roughly and dies when put in gear or just sitting idle.

I suspect the ECM might be the issue. I’ve checked all connections and inspected for water damage, but everything looks fine. I know testing the ECM is difficult without the right tools.

I'm at my wit's end. I called the shop again, but they are stumped and don’t know how to tackle this problem. They have more resources than I do, but I'm getting increasingly frustrated.

Has anyone experienced something similar or have any suggestions on what I could try next? Any advice would be greatly appreciated.

Thanks in advance!

Unfortunately since I a new to the forum it would not let me post this under the Gen 5 page. Forgive me if this causes any inconveniences.

 

Sorry nobody replied. I normally get a good response from the guys here. I wish I could help, but I am having the same issues with my gen3….

 

Is the MAF sensor a Denso? The shop is correct. Toyota traditionally doesn't do well with aftermarket ignition and fuel system parts.
We don't see a lot of these issues, so there aren't many people who have dealt with this.

 

possible rodents chewing on wire somewhere? I hate chasing electrical issues after you buy all new parts. Might be a trip to a dealership ti diagnose

 

Unfortunately you will have to find someone who can take the time out to figure this one out, maybe keep it for a few days also. Most independent garages I know do not have the expertise or the inclination to do such a job.
A trip to the dealership is an option but that's a double edged sword. When they see high milage 4runners, they start telling you random parts needs replacement without actually understanding the problem.

 

Unless water somehow got into ECU, I would not assume this to be the cause until every other option is exhausted. Rodents and wiring harness damage is a plausible explanation.

Also, have you checked for bad fuel? You could have had bad coils and bad fuel, one issue fixed but another is still there.

Another guess - check crank position sensor. While you don't have a code for it (P0335) symptoms seem to be consistent with one that is failing and giving bad readings.