Question - What is the cause, what will fix it and if it is the carb
what would be best choice for improved gas mileage and dependability.

I started having issues with my Mustang 5.0 1985 carbed, 5sp lately.
The engine started hestating and idle would surge from high to low,
it also smelled of gas strongly. I took it in and they said they
found some leaks in the carb and fixed by tightening. I have had the
module replaced 2 years ago, carb rebuilt 2 times, mostly due to the
module recall. once that was replaced it ran fine. So, while trying
to trouble shoot I look and seen the cat glowing red hot. I had it
replaced and it still will start fine but after getting warm it will
glow and then the engine starts to pop and run rough. The popping is
in the exhaust. The mech, says it is the carb, one bank is running
lean and needs to be adjusted but the carb has no adjustments. He
says replace it and it will fix. The past mech, said the smog pump
should be bypassed. What can i do to determine cause of glowing cat
and engine running rough? I did recently (2 years old) swap the
orginal exhaust from a 2 into 1 into 2 to a true dual exhaust with 2
cats and H pipe etc. After replacing the cat the same one is glowing
the original side if that helps.

Below is a local mech, answer, but I informed him I only think it is
the cat not the exhaust. He said, not my area.
Answer -
Anthony-

A glowing red exhaust is almost always a sure sign of a lean
running motor. The increased cylinder pressure makes the exhaust
super hot which, in turn, makes the exhaust glow. If you're still
using the factory Motorcraft carb, I'd just ditch it in favor of
something like a Holley 600cfm double pumper. They're more reliable,
can be adjusted pretty easily, and you'll probably even pick up a
little performance

 

But I have been told that is not possible it needs them for inspections. Also if the engine is running that hot does it not cause more damage? I am up for removing but they are sometime tricky here with inspections in MO.

 

I would find a good used carb, like edelbrock, I like demon carbs,onebay and try that cause that is a sign of running lean and the super hot gases are creating it to glow. the exhaust might not glow but those cats can glow easier. Sometimes if you have after market headers they will glow also. I would try changing it out as soon as possible so no serious damage happens.

 

Go to a different county in Mo to have the inspection done.No smog inspections in most of the state!!

 

Also how is your timing chain, is it stock or did you replace it. I know if you changed it and didn't install it right or if it's old and it's stretching, your will have the valves off and it can cause things to glow...