2000 Lexus ES300 Misfire Detected, Cylinder 2, 4, 6

Hi! I really have serious problem in my car. My check engine light came on one day and car was shaking very bad. I found out through auto zone that I have Misfire detected in Cylinder 2, 4 & 6. When I got home, I couldn't start my car the next day. I local mechanic came to my house to see the car. He checked there is spark in the ignation coils but spark plug was full of gas. So all the spark plugs were flooded with gas. He told me that the problem seems to be fuel Damper Assy. I bought the Damper Assy. He replaced it and car started fine. But after then min driving, same issue. Misfiring. After twenty min driving. I open the hood, the front cat converter was red hot. Like a red globe. He thinks there is still same issue. Front cylinders too much gas issue that's why front cat converter got too much red hot. He'll take a look in a week but I’m requesting if some one can help me out or have seen or heard this kind of issues. I’ll really appreciate for any help. Thanks.