P0301 after driving through 3 feet of water

[auturner]

2011 edge sel 129xxx miles. Drove it through some water in mississippi a month ago, since then im getting p0301 code- misfire on cylinder 1. changed coil and plugs. light went away for a few hours then came back flashing. drove it through 3 feet of water. no water in oil.

[WWWPerfA_ZN0W]

check the PCM connectors for water intrusion.  If water got in there, a good cleaning (and adding a dab of dielectric grease) may be all you need.

[auturner]

okay, ill check the pcm. in the meantime i changed fuel injector and pcv valve. and im still getting the p0301 code. thanks

[auturner]

P0420 - catalyst system efficiency below threshold bank . this code is whats showing up now. got rid of the p0301. do i need to replace the catalytic converter? or is there any sensors or anything i can check or replace first? i have a obdii reader with live datastreaming but i am not mechanically inclined enough to look at the data streaming to be able to pin point what exact type of issue im having.  

[PaulSchott]

It could be bad O2 sensor but it could also be the Cat.  Water in the O2 connector,  driving with a blinking check engine light will overheat the converter by dumping raw gas into the exhaust.

I would check the O2 sensors first.