I have a 1994 4.3 litre and I knocked the guts out of my catylitic converter and I have been told that fuel injected systems need the back pressure of the cat I am wondering if this is true.

Besides being a Federal violation, the egr system needs some back pressure to operate.

You might want to edit that one part out of your question....just a thought...:lol:

I have a 1994 4.3 litre and I knocked the guts out of my cat and I have been told that fuel injected systems need the back pressure of the cat I am wondering if this is true.

i don't think removal of the internals will change back pressure too much, if it does then that cat was plugged....you will emit pollutants when engine is cold, and if engine is not running properly....if you notice that the engine has better power then it must have been restricted...

if your engine is running properly , if it is required in your area , the emissions testing , it is possible that it will pass...

if the removal does cause a pinging you may have to install a different egr that will allow more flow....