Trouble Code P0306

[4x4mike]

So it looks like I have the dreaded P0306 code, misfire cylinder #6. I got a pending code on my Ultra Gauge on the way home from work and by the time I pulled into the driveway it was a full trouble code. My code reader also pulls up a P0306 and nothing else in the DTC's. I did a quick google search while I changed clothes then decided to drive it around and see what was up.

After doing a little reading and throttling I ended up at the dealer. Truck starts fine but then has a bit of a grumble. Idle is a bit low, under the regular ~750 RPMs. The exhaust also has a lub-lub sound, not normal. There is a loss of power and the miss, along with hesitation is very noticeable on acceleration (1st and 2nd gear) and driving in reverse. I've cleared the codes and under heavy throttle I can get it back, otherwise it logs as a pending.

I have a spare coil pack so I took the time to replace the middle pack (my Haynes manual says this controls the #3-6). No change. I also moved the spare coil pack to the front and rear positions with no improvement. While at the dealer I picked up new wires and plugs as they have very close to 84K on them. Visually they are fine but I figured I needed them and it would be a good way to isolate the code. After changing the wires and plugs I still get the code and there is no improvement in idle or acceleration.

I just got back from Pismo and put a flawless 700 miles on the 4Runner. I got 20.8 mpg on the way down and 21.3 on the way home. I used Chevron gas and had no problems during the trip or reefing on it in the dunes.

The remainder of my google searches talked about replacing injectors. What's everyone take on this? I'll have to go back to Bob's post about his injectors but in a simple search it doesn't look like he got the P0306 (Sean did though). Napa has a re manufactured injector for ~$60 and new (Napa brand) around ~$120. I didn't get a price check at the dealer but I'm guessing higher, if available. As important as a part as this is I'm not too hot about dumping a lot of money into the 4Runner. Just a few weeks ago I was test driving potential replacements (should have driven my wife's car there, it's on to me).

Later tonight I'll try to upload some pictures and do some more reading. The plugs looked fine, as did the wires. I couldn't see any arc traces on the coils, boots or wires. If I go the route of replacing the injectors, should I replace all of them?



One side of spark plug from cylinder #6


Other side