Hollow cat performance issue

[PaulKersey]

I know it's illegal, but my 1989 F-250 arrived with a hollow cat. I installed a re-manned 460, and still lacked the power it should have. I was also stalling occasionally from a dead stop. I pulled the old O2 sensor and immediately picked up power and cured stall issue, so I replaced it. Old 02 sensor I think always showed a rich mix and leaned out the engine. I still feel there's more power to gain. Could the hollow cat be responsible due to lower back pressure or another reason?

 

[Beach66Bum]

If the exhaust is to free flowing, you will lose some power on bottom end.
Keep all the factory sensors and go with a quality cat back exhaust for the best in performance and mileage.

 

[SuperCab]

I don't know that having a cat or not would make a noticeable enough difference in power... what makes you say it's lacking power?

 

[PaulKersey]

I also have an '87 F-250 with a 460, and there is a significant difference between the two. Are you suggesting that a deleted cat has no effect on o2 sensor readings or air flow?

 

[PaulKersey]

that makes sense. I'll first attempt to restrict air flow through the hollowed cat and see if that helps. If not, I may go ahead and replace it. Thanks.

 

[dustybumpers]

Power difference could be rear gearing.

Cat shouldn't matter, but if there is a fuel problem that caused the cat to fail, and the previous owner to gut it, you should fix the problem.
Have you pulled the codes yet?

 

[dustybumpers]

replacing the cat without fixing the fuel problem will cause the new cat to fail

 

[PaulKersey]

Any previous issues were resolved with the new engine, and there are no codes. When I deleted the o2 sensor of course I got a code for that. The power issue I believe has to do with air/fuel mixture. I think the decreased back pressure is causing a lean fuel situation. I'll know soon