Once I removed the cat on my 460 89 ford f250 it runs but bogs down once I push the gas pedal. I need to gut the cat and drive it to a shop to have the cat welded back on. Is there something I need to do to make it run fairly smooth so I can get it to the shop? The two pipes on top of the cat that I cut out, do they need to be capped with something for it to run smoothly enough for me to get there?

 

It should run just fine with the cat removed so you have other problems. Have you checked fuel pressure and pulled the codes?

 

Yup, with no cat it should run better if anything, never worse.

Did you damage the oxygen sensor while you were under there? I don't remember where it is on that truck but the sensor needs to stay in place... everything downstream of that you can do what you want with.

 

I took out my cat a month ago and actually saw a big increase in performance. You must have done something wrong the the 02 sensor or maybe the egr tube

 

O2 sensor on that truck it in the Y-pipe right where it comes together in front of the cat. What was it running like before you removed the cat?

 

It was running just fine prior to taking the cat off and it still runs fine but pushing on the gas pedal bogs it down. It might be because I don't have much gas in it. I did notice that it idles fine but will bog down once I push the gas. I thought the two tubes had to be plugged or something had to be done with them but I could be mistaken.

 

Uh yea, gas in the tank helps a lot.

 

Haha LMAO this cracks me up right now... I'm sure the beer helps too. I went to look at a CCLB F-250 once, the gal selling it (per her boyfriend's request, said it was his project) had NO gas in it according to the gauge, but she claimed it would be fine and the gauge was off. So I took it for a test drive and made it maybe 3/4 of a mile before the 460 sucked the tanks dry... I told her no thanks. If she can't be bothered to keep it ready for a potential buyer to drive, no telling what else was neglected while they owned it.

Anyway, not to hijack this thread, get some go juice in there and try again. Should run better without the cat. If you mean plugging the air injection tubes, don't bother. Just ditch the smog pump and plumbing altogether.

 

The beer didnt help at all and I'm more then positive that the gas that I put in there wasn't sufficient. I was more worried that the smog tubes might be causing the trouble and wanted to make sure they werent the problem. Thanks to all and will update tomorrow.

 

No I meant the beer was helping me to crack up at the no gas comment. Hopefully when you read this today it'll be right before you post and say that the truck runs great now.

 

I should be able to hear the fuel pump run in the rear tank if I have someone turning the key for me. I don't. I believe that the rear fuel pump isn't going because it's not running at all anymore with gas in it and there is no fuel pressure at the rail. It's like I hit the fuel shutoff. I have ordered a new front tank and will update when it comes in. Thank you all for the help.

 

I am planning on doing this (removing the cat) in a few months. Is it really that big of a difference?

I'll be hollowing out my front cat and replacing the 50-state legal rear cat with a 49 state legal on. I thought I'd gain some but will it be that significant?

 

You should only have one cat. Your headers go into it. The next is the muffler.

 

Nope, I have 2.

 

My 460 has no cat and has power for sure. But sometimes it hesstates when i am idleing and step on the gas. It used to idle around 950 when warm. Removed cat it idles at 500 when warm.