Ah, sorry about that.
I should have noted, that when the chunks came out the exhaust it was running super lean. That was when # 1 piston got partially melted, two plugs had their electrodes completely burned way, & most of the others weren't much better. This was all before the current rebuild.
You might want to check out my Member Page for the current mods.
I'm currently running a tuner with a Dr. Fred file, so the parameters are fixed with the fan comming on at 190* & 195*, obviously while it stays cooler in town.
I considered pulling the board, but 1. don't want to have the fan holding off to the factory temps and 2. the O2 sensors are probably gonna tell the EEC to lean the heck out of the mixture. I really don't think adding more heat to the situation is a good idea at this time.
This is another point which is confusing; it just passed smog testing last week in one of the toughest counties in CA.
Additionally, after the rebuild, there was an exhaust leak at the left side header and downtube. A muffler shop fixed that but said there was still a leak at the head/header. Immediately after the rebuild, that was checked, the gasket was evenly compressed and a 2nd one installed. There's also a loud rattle in the rear exhaust which doesn't appear to be any part of the exhaust hitting anything.
So here's what we're wondering; if the CAT's are partially melted/broken with pieces partially blocking the exhaust in the resonnator and/or the mufflers, what would the symptoms be?
There would certainly be a lot of heat build up in the exhaust, which in turn , as you pointed out, would cause most everything under there to heat up. The engine would be fighting the restriction which may be moving back and forth creating the feeling of driving into an inttermitant stiff wind. That's what I meant by it felt like the car was fighting itself.
As far as the rich mixture, Fred said he was going to be conservative in the #'s considering what happen before. So, it may be set on the rich side. I'm not sure why that didn't show up in the smog test, since that is done dymanically under load, although not at hyway speeds.