[stich]

Originally Posted by JLMounce

It pops out of the exhaust during steady throttle or on deceleration?

Popping out of the exhaust during steady state throttle or during rpm acceleration would be really weird. Popping out of the exhaust is commonly caused by excess unburned fuel exiting the combustion chamber and reigniting in the exhaust pipes.

Does the AFR show rich when this is happening? If not, I would take a good look at where the oxygen sensor is installed and for any exhaust leaks upstream, or within 18 inches downstream of the oxygen sensor.

You didn't state whether or not you were running timing control. If you are, popping and missing may indicate that you have spark that is jumping terminals. This would be caused by the rotor and cap being out of phase. Consequently, this may also be part of a hard start issue.

Pops on accerleration only No timing control, no exhaust leaks that I hear.