Last week I had a coolant line burst and had to have it replaced. It was the one that attaches from the upper radiator across to the thermostat hsng. comes as one large piece. The car did not over heat but the temp did rise some as I got it off the highway.

I steamed off the engine once I replaced the line and the car ran fine. That evening the car developed a misfire. I read the codes the following day (the misfire seemed to get worse over time and isn't bad at idle, only under throttle and worse when in passing)

the codes are 0303 cylinder 3 misfire
1313 misfire rate catylist damage fault Bank-1
1316 misfire ratre exceeds emissions

any advise would be greatly appreciated

 

Sounds like the coil on Cylinder # 3 is wet or the steam/water created or made a minor short in that coil worse and has rendered it useless.

Not the greatest idea to steam the engine under any circumstances.

Check the coil and connector to the coil. Also, check the connection to the fuel injector on cylinder #3.

If no water is evident - change out the coil and DO NOT drive until this is resolved to avoid creating more issues like burning out your catylist (converter).