Fixed. Very easy fix. But this is a case where I knew too much but didn't know 1 very important thing. A little refresher. This thing starting misfiring on the highway and I connected my scanner and it had misfires on #1 and 2 cylinders. They both started at the same time and they both misfired at exactly the same time. That's what made it so weird. On the day it happened I replaced the plugs on engine bank one and moved #1 coil to #3 cylinder and vice versa. (I didn't change the bank 2 plugs cause I was working in an Advance Auto Parts parking lot with a terrible set of tools.) That didn't change anything. Later I switched the #2 coil with another one. Still no change. I had to leave it at home for the last month while my wife and I were out of town. So the first thing I did today when we got home was call Identifix. The Toyota specialist there told me the one small thing that I didn't know about Toyotas, even though I've been working on them for 30 years. That is: You can't trust the misfire monitors on a Toyota. Mine was telling me it was misfiring on 2 cylinders. He said it could just be one cylinder and it could be a totally different one than either of the ones it said it was. So I went to it and did a power balance test and found out it was misfiring on #2 cylinder only. So I set out to move another coil to that cylinder. I decided to go ahead and put the other three plugs in while I was there. So I put them in and switched #2 coil with the #6 coil. When I started it up there was no more misfire. I expected it to misfire on #6 but no, no misfire. I drove it about 5 miles putting it under a load, (which is when it misfired the worst). I watched it with the scan tool and there was not a single misfire. So the final verdict is a bad plug on #2 cylinder.
What's so funny is any backyard mechanic would have fixed this just by replacing the plugs. And truthfully I didn't spend more than about an hour total working on it. But I spent many hours thinking about it. Because I'm an experienced technician I was able to rule out many things that it (couldn't) be. Just by learning that the misfire monitor is not reliable was all it took to figure it out. I thought if it said #1 and #2 were misfiring, they were. But, anyway, I'm very happy to have it fixed without spending a lot of time or money on it. I may go ahead and order a set of coils for it anyway. And as I've learned over the last 30 some years, when it comes to auto repair, never say never. I'd like to sincerely thank everyone who offered help with this. I do appreciate it. And I will continue to offer my help to anyone else on here when I think I have something worthwhile to say. Thanks guys.
What's so funny is any backyard mechanic would have fixed this just by replacing the plugs. And truthfully I didn't spend more than about an hour total working on it. But I spent many hours thinking about it. Because I'm an experienced technician I was able to rule out many things that it (couldn't) be. Just by learning that the misfire monitor is not reliable was all it took to figure it out. I thought if it said #1 and #2 were misfiring, they were. But, anyway, I'm very happy to have it fixed without spending a lot of time or money on it. I may go ahead and order a set of coils for it anyway. And as I've learned over the last 30 some years, when it comes to auto repair, never say never. I'd like to sincerely thank everyone who offered help with this. I do appreciate it. And I will continue to offer my help to anyone else on here when I think I have something worthwhile to say. Thanks guys.
