Hi, I've searched and read several pages about misfires but haven't found one exactly like mine.

I have a 2000 4runner SR5, 3.4L, 5spd, 4x4, plus 330K km's

I'm getting a #2 cylinder misfire code and the engine runs very rough when warm.

The problem started after I replaced both O2 sensors (but that might just be a coincidence).

I have replaced: all plugs, coils, wires, all 6 injectors, and the MAF.

Did a compression test; all 6 cylinders good.

Thought it was the MAF. When replaced and taken on a test drive at all speeds the truck ran fine and no codes.

Let the truck cool down, started fine, drove it a short distance and shut down. Then restart (engine still warm) and the engine light came on and the engine ran very rough.

RUns fine on a cold start and runs rough and engine light comes on with a hot start.

This problem seems to usually be the injector but I replaced all 6 and still have the same problem.

I'm not getting any other codes. I've replaced all the usual suspects and don't know what else to do. And it's getting pretty expensive at this point.

Any help would be appreciated

 

have you checked to see if you have a vacuum leak around that cylinder? if you have replaced the plugs, wires, coils and injectors you have to have a vacuum leak unless you put on a faulty part.