I have a 1999 4RUNNER SR5 4WD 3.4 V6 WITH AUTO TRANS.

I am not getting my miss resolved. My compression test averaged 198 psi for the 6 cylinders. I replaced all of the wrong type of plugs with denso plugs. replaced the coils and wires. no joy. replaced the injectors. no joy. replaced the maf, and O3 sensors, one of which was dead. no joy.

When the engine warms up from cold a rough, rolling miss develops, and I get "lean on bank 1 sensor 1" which I replaced.

BUT> if I run the engine with the maf sensor unplugged, which at least gives the correct intake air temp, the engine settles into a very smooth and normal sounding idle, with no missing. The problem is that the injectors are wide open and I can't safely run the engine full rich.

I keep looking for clues in the FSM, the WIRING DIAGRAMS, but no good ideas. I am posting this in the Hope that someone somewhere has solved this issue and knows what I should look into next. I would gladly take this to a mechanic, but don't want to run it the ten miles there in the condition it's in.

I've read lots of very similar on all the Toyota forums, but never find detailed steps to pursue at the point this runner is at.

If you've solved this issue, pls message me or post here.

Thanks and Gratitude in advance

Michael sends