Hello everyone, I am new to this, so please be patient. I would like to thank everyone in advance for any help you may give. I have a 1999 Toyota Corolla with a lot of miles! It has been a great work car. I started having some problems recently that I just cant figure out. My check engine light had been on for some time, but the car was running fine. The car has 300k miles on it. Never had a problem. In the mornings when the car is cold, or after it has sit for a few hours and then engine is cold, the car doesn't want to start. It is like it isn't firing or getting fuel or something. I pulled the codes and it gave me a P0420 and P0115. As I said earlier, the light had been on for a while with no problems. I cleared the codes and the light came on again with P0420. I get the P0420 code everytime the light comes on and the P0115 occasionally. Anyway, I crank and crank and finally I will get the car started. It will run really rough for a just a little bit and then smooth out. From that point on it will run just fine with no problems. I just put brand new NGK plugs and new plug wires on the car, and that didn't fix my problem. Any thoughts?