So about a month ago I bought a 2002 nissan maxima $1200 from a private seller and it drives fantastically, no codes or anything (Maybe they were cleared and came back later)

Anyways, I did a couple repairs:
-Replaced both valve covers due to a leak on both

-Replaced all coil packs and sparkplugs

-Replaced intake manifold gasket

During the repair the crankcase breather hose snapped and I didn't have the money to get that hose so I went to an auto parts store and got some heat treated bendable tubing and fit it in, works great.

The people I bought the car from also double as a mechanic and at a lower rate, took it to him and checked the catalytic converter to see if it was holding heat and the temps seem to be normal. When we were checking the temps we were also checking for pin holes in the exhaust system to see if I was getting too much oxygen causing the o2 sensors to read incorrect information and we found that the muffler wasn't connected to the rest of the system and that it was dangling there essentially not connected.

So mainly I would like to know if this could cause the p0430 code (I originally had p0420 and 430, 420 didn't come back after we tightened a hose connected to the intake manifold)

Thanks in advance!