Check engine light blinking, 2003 Ford Police Interceptor?

Check engine light blinking, 2003 Ford Police Interceptor?

Added (1). Read my comment for the description, its "Kevin". It was too many characters to add in here.

2003 Ford Police Interceptor (crown vic) 102, XXX miles. It had a solid check engine light on for 2 months, it was O2 sensor failure bank 1 sensor 1. I suspected that my catalytic converter was clogged, smelled like it was and it puffed air out. My car also had a failing coil pack. So today I decided to replace spark plugs and seafoam my car. I was able to replace the 4 spark plugs on the drivers side with no problem, besides i had to remove the air intake hose thingy to get to them on that side. I then moved on to change the other side. I was able to replace the most upper front spark plug but I couldn't replace the rest! The middle far plug looked like it was pealing metal and I couldn't get the socket around it. The middle close plug had a tiny bolt jammed between the spark plug head and that little chamber the top sits in, so I couldn't get my socket around it either. The closest spark plug closest to the firewall, I couldn't even remove the coil pack at all. I said "**** it" and I put the coils back on and connected the battery. Then I turned it on, still had a normal check engine light on not flashing and my ride wasn't all that rough running. It felt like there was no difference. I then seafoamed it. I removed the brake booster line to pour the seafoam into the vacuum line. That was normal. I turned the car on and revved it, and white smoke came out of the exhaust (normal for seafoam). Before I went for a ride the engine light was its normal solid color. I then went for a drive on a road in which speed limit was 60. And thats when all hell broke loose. I gave it gas a few times on the road. I can hear and feel the engine misfire, it was hard accelerating and power was inconsistent in the engine during acceleration. I got home and that's when I realized it was flashing. I was also able to smell more of a gas smell. I was only out for about 15 minutes. My mechanic is like a 4 minute drive from my house. Should I still drive it to the mechanic, or tow? What could of caused the flashing check engine light? Is my catalytic converter at danger? Costs?

Seafoam causes engine failure.