Here we are again. My daughter bought this car 6 months ago. 291k, had misfires. I replaced all three cats, all plugs and cops. The firewall cat has three bolts broken off in the head. I used a soft double gasket, and it held for three months. The loss of power started when we noticed the exhaust manifold leaks. I redesigned the double gasket by adding 700° RTV copper and a regular steel gasket in between the two soft gaskets, only at the one that had no bolts. No audible exhaust leaks. I also replaced all of the crumbling vacuum lines. Now, I still have no power, although it idles well. It does start a little harder when warm.

There are no codes showing with my code reader, no engine light.

What is the likelihood of my EGR being clogged? I pulled the vacuum off the EGR and got no idle change.

Thanks!