I have a 2012 FJ(ATM 4x4) with 85k miles. I have owned this vehicle since new and all the maintenance for the first 4 years/60k miles was done at a local dealer in Ann Arbor, MI. After that point I did my own maintenance, regularly checking things to be sure there were no issues. So far, other than the frame/suspension rust that comes from living in SE Michigan, everything has been perfect. The donut gasket in the exhaust is leaking a little, but I'm saving that for warmer weather since it is guaranteed to be a PITA to fix due to rust.
On Christmas day 2021, I drove ~230 trouble-free miles from my parents house to my own. Everything was running fine, no issues. The truck sat for a week or so since it doesn't get used much while I work from home. I decided to fire it up to make a run to the store one day and I had a flashing CEL and the Trac light came on. I cancelled my trip to the store and went to Autozone to get the code scanned instead. P0306 - Misfire in Cylinder #6. and this was the ONLY code being thrown.
So I figured, OK, its got 85k miles, probably spark plugs and maybe a coil needs replaced. I get a deal on parts at the dealer, so I went in and got a set of plugs and ordered a coil. The old plugs weren't terrible, but weren't great either, and all looked the same. From that I know it wasn't the plug on #6. When I put the coils back(since I had to wait a couple days for a new one and time to install it) I went ahead and put the #3 coil on the #6 cylinder and vice versa. That way, swapping the coil would be easy when the new part arrived and I could see if it was indeed the coil. Fired it up, went to Autozone, scanned it, still getting P0306 and nothing else. Bummer, but least it isn't the coil.
I've had issues with Red Squirrels in a 4Runner I had for a while, so my next effort was to confirm the wiring was actually OK. The little bastards have torn out some of the firewall insulator, so I thought it might be possible they got a harness. So I pulled the Wiring Diagram from TIS and Checked continuity for the #2 and #3 Coil pins at the ECU and confirmed correct voltage for #1x#4. Everything is good.
Now I'm stuck. From reading on here, it seems there is possibility of a head gasket leak. However, I don't get white smoke from the exhaust and the coolant still looks clean. The oil also smells/looks ok, but I have only driven #2 miles total with this issue and maybe another 15minutes worth of idling in the drive as I try different things out. I can't wrap my head around a few things and I'm trying to rule out/test as much as I can without taking a bunch of stuff apart since it is 20degrees out and I don't have a heated garage.
Some Questions:
1) If an injector was leaking, wouldn't I get a code from the O2 sensor?
2) If it were an O2 sensor issue, wouldn't that throw its own code?
3) If an injector was plugged, wouldn't that also cause an emissions or other code?
4) What else could I be missing that I can test?
On Christmas day 2021, I drove ~230 trouble-free miles from my parents house to my own. Everything was running fine, no issues. The truck sat for a week or so since it doesn't get used much while I work from home. I decided to fire it up to make a run to the store one day and I had a flashing CEL and the Trac light came on. I cancelled my trip to the store and went to Autozone to get the code scanned instead. P0306 - Misfire in Cylinder #6. and this was the ONLY code being thrown.
So I figured, OK, its got 85k miles, probably spark plugs and maybe a coil needs replaced. I get a deal on parts at the dealer, so I went in and got a set of plugs and ordered a coil. The old plugs weren't terrible, but weren't great either, and all looked the same. From that I know it wasn't the plug on #6. When I put the coils back(since I had to wait a couple days for a new one and time to install it) I went ahead and put the #3 coil on the #6 cylinder and vice versa. That way, swapping the coil would be easy when the new part arrived and I could see if it was indeed the coil. Fired it up, went to Autozone, scanned it, still getting P0306 and nothing else. Bummer, but least it isn't the coil.
I've had issues with Red Squirrels in a 4Runner I had for a while, so my next effort was to confirm the wiring was actually OK. The little bastards have torn out some of the firewall insulator, so I thought it might be possible they got a harness. So I pulled the Wiring Diagram from TIS and Checked continuity for the #2 and #3 Coil pins at the ECU and confirmed correct voltage for #1x#4. Everything is good.
Now I'm stuck. From reading on here, it seems there is possibility of a head gasket leak. However, I don't get white smoke from the exhaust and the coolant still looks clean. The oil also smells/looks ok, but I have only driven #2 miles total with this issue and maybe another 15minutes worth of idling in the drive as I try different things out. I can't wrap my head around a few things and I'm trying to rule out/test as much as I can without taking a bunch of stuff apart since it is 20degrees out and I don't have a heated garage.
Some Questions:
1) If an injector was leaking, wouldn't I get a code from the O2 sensor?
2) If it were an O2 sensor issue, wouldn't that throw its own code?
3) If an injector was plugged, wouldn't that also cause an emissions or other code?
4) What else could I be missing that I can test?
