can code 0420 result in transmission going to limp mode

What is your question?

i have had code 0420 come up for quite a while now and i suspect a leaking intake manifold gasket. lately the trans as been going into limp mode and i was wondering if the continued presence of coolant leak into yhe intake would cause trans to go in limp mode. another question is if i fix coolant leak do i need to replace catalyctic converter?