p0422, p0455 codes, loss of power

[travislgrice@gmail.com]

Greetings. I have a 2.2L 4-cyl 2005 Pontiac Sunfire that recently gives codes p0422 and p0455. There may be a leak in the exhaust system but I don't know where. Recently I mistakenly added old gas to it that was sitting for about 2 years, but have since used Seafoam to stabilize the remaining fuel and have refilled twice. I also just replaced the catalytic converter. I just installed new spark plugs and an air filter. There doesn't appear to be a leak in the gas tank or evap canister. The gas cap is on tight. When I hit the gas, the car doesn't accelerate as quickly and the engine is much louder than it was about a month ago. What should I do?

 

[melsg5]

the car has to be put on a lift and checked for the exhaust leak which maybe related to the replacing of the converter. https://www.obd-codes.com/p0422
the evap system has to be checked possibly with a smoke test to determine where the leak is https://www.obd-codes.com/p0455