When putting my new wheels n tires on today I noticed my exhaust was hanging down, upon further inspection I found multiple hangers rusted through and broke. When I went to remove just the tail pipe so it did not fall off while driving the whole exhaust pulled off the Y pipe, cat and all.
Then I found my Y pipe to be cracks and the tip is ovaled.
It's going to be awhile till I can afford new exhaust and a Y pipe so what problems might I run into running basically open headers.
I have a 90 4.9L inline six if that matters.

 

Do NOT run open headers! It will ruin that good ol 300. Try to get some kind of exhaust on it. If you dont have the cash for a new exhaust maybe check the wrecking yard for a decent exhaust system

 

Sad face. It sounds so good!
I'm going to get the cat back on the Y pipe and do a tailpipe of some sort but there is no chance of a muffler right now.

 

yea try and get some pipe under there ...who cares if its aluminized steel, open headers=NO NO

 

I'm going to use what piping I have and weld up the Y pipe, put the kitty cat back on and just do a short dump. Will this help or is it still bad?

 

I've been running just a y-pipe for a while with no problems

 

It will be a dog on performance. Weak low end. Get some velocity and static pressure going on, get an exhaust.

 

I absolutely love how it sounds but it is almost too loud, I can't barely hear the radio when it's up the whole way and I can't talk on the phone unless it's in neutral.
The cat is goin back on with a small dump.

 

meanwhile save up for a decent exhaust!

 

New Y pipe and dynomax duals very soon.

 

I hope you don't mean Bullets. On a 6 cylinder, everything straight-through sounds awful. Keep it stock, or go for a chambered muffler.

 

Why? I seen it done on stock mustangs and camaros, as well as a few older F-150's and older chevys, sure its not going to be the best thing ever, but its not going to destroy it.

 

Yes it can, not immediately, but it will drastlcally reduce the life of the engine. Cracked or warped valves are the main issues that arise from running open headers.

 

it must take a really long time, or that mustang owner is really lucky, hes been running open pipes for about 3-4 years now. just open headers back to a single collector and dumped about half way under the car.

I never knew it would cause damage, I thought it was just a myth.

 

Well then it's not open headers. Open headers is just a set of headers and that's it.