After replace the IACV, the sypthom seems go away.
However, now it comes back again and engine occasionally dies off at N or D position.
Sometimes, after restart the engine, it dies off immediately, so I have to press the accelerator pedal to prevent rpm from dropping, else it will drop to 0 again...
Sometimes, while driving the rpm drop to zero and the engine dies off while I release the accelerator pedal. But sometimes it manages to bring up the rpm back to normal immediately after rpm drops almost touching 0.
Morning start, sometimes very smooth, sometimes coughing but no difficulty to start.
Mechanic suggest to change IACV and AFM. But I check around, my symthom is different from those who face the faulty on AFM. Also no error code found.
One thing I notice is the tail of the exhaust pipe is very dirty, full of carbon which was built up recently.
Any ideas?