Iparkcars

I have 03 lexus gs300. I tired forever to track down a 442 446 code on my car it end up being a Crack in the pcv elbow. I replace it with a piece of hose from the auto part store. I then had a check engine light come on with a p430 code. I looked again. And realized the hose I used to replace the pcv elbow was collapsed in where it bend had occured.I used a regular piece of hose because the actually pcv elbow hose from lexus was 22.00 smh.. I replaced it again with a longer hose with no bends in it and the check engine light came back on. I look over the hoses again and there was a small Crack in another vaccum hose so I replaced it. I started reading and see alot of people talked about the cat being bad. I became very nervous hearing this.I went and purchased a infared thermometer to test the cat temperture. I let the car idle for 15 mins the reading that I got before the cat registered around 230 degrees after the cat was 155 to 160 degrees. I was wonder if this sounds like a bad cat reading. I haven't changed the 02 sensor since I brought the car 35k but 133k on the car.I was also wonder should I just spend the 22 for the pcv elbow hose because that was the old be the issue and i didn't start getting that code til I replaced that hose The car has good pick up no rotten egg smell. I was wondering if you all could lead me in the right direction. Thanks in advice for your help