Transmission or spark plugs

[pitterpat]

Since I got the SES flashing solved and the multiple misfires on cyl 4 & 8 solved a new problem has cropped up. When driving the engine will like lurch or stumble. I'm thinking is the transmission or the spark plugs. It did it several times on the expressway today so that's why I think it is the plugs. Or could the transmission be slipping?

Thanks for all the help.
Pat