prob not - if back pressure got too high if the internals come's further apart it would just quit running due to lack of exhaust flow .......

Thanks for helping me out
 

Would the cat breaking up cause the rearend to shake???

Depending on what you mean by shake but A multi hard miss prob would

Thank you for your help.
 

just got it out of the exhaust shop. No symptom have been repair. With the exception of the rattle and the vibration of the rearend. It is still missing and popping.
One more thing this all started with no warning. It almost seems like someone sabatoged my truck.

OK, so the exhaust shop replaced the cat? And now the rattle and vibration is gone, but it still misses and runs rough?

Thank you for your help.
 

Okay, yes the cat has been replaced with a straight pipe.
Took it to AutoZone. It threw 5 codes 2 0300
0171. And 2 0101.
The code reader says the blazer needs a fuel regulator.
Which makes sense because half of air filter is missing. Me and buddy are now tear apart the carb(injectors) to replace this part. Hope this fixes it.

Did you actually check the fuel pressure, or are you just throwing parts at it? Fuel pressure is super easy to replace, and can determine if the injectors or pump is at fault

Thank you for your help.
 

This is what was recommended.
Don't know.

Thank you for your help.
 

If it helps we are in a full tooled logging shop.
I work in the logging industry. I have access to a full tooled shop.

Thank you for your help.
 

And all the computer readers are locked up. Don't have access to those.