Wondering if I can remove the cats and computer
Thread Starter
|
Senior Member
Joined: Sep 2006
Posts: 140
Likes: 0
From: Charlotte, NC
Originally Posted by Radio
I gutted my cats on my 95 5.0 and had some serious fuel efficiency increases just clicky on my signature.
I read your post. I can't figure out what your mileage actually is now. I think we've got the same set up. 302, 5 spd. I've still got the stock 3.55 ratio. What do you think you get per gallon, just normal driving around. Also, have you got the stock manifolds still on or headers?
Senior Member
Joined: May 1999
Posts: 2,477
Likes: 0
From: Copley, Ohio
Originally Posted by selbona
Alright, so I'm stuck with the EFI and the computer unless I want to completley gut my truck and start over. So, if I cut the cats off, does anyone know what will happen to the sensor readings in the computer? I guess it's going to throw a code, but what, if anything, can I do to bypass it?
If your cats are functioning properly, do not expect to see any MPG gains by removing them. If they are clogged, that's a different matter.
Senior Member
Joined: May 1999
Posts: 2,477
Likes: 0
From: Copley, Ohio
Not true.
With or without cats, the EFI system requires that ALL upstream HEGO sensors remain functional. On 96-up vehicles with OBD-II there is a downstream HEGO sensor between the cats and the muffler. If you gut the cats on an OBD-II vehicle you must install a MIL-eliminator on the downstream sensor. The upstream sensors MUST remain functional regardless of OBD-II or not.
With or without cats, the EFI system requires that ALL upstream HEGO sensors remain functional. On 96-up vehicles with OBD-II there is a downstream HEGO sensor between the cats and the muffler. If you gut the cats on an OBD-II vehicle you must install a MIL-eliminator on the downstream sensor. The upstream sensors MUST remain functional regardless of OBD-II or not.
Senior Member
Joined: Feb 2004
Posts: 10,390
Likes: 10
Originally Posted by StrangeRanger
Not true.
With or without cats, the EFI system requires that ALL upstream HEGO sensors remain functional. On 96-up vehicles with OBD-II there is a downstream HEGO sensor between the cats and the muffler. If you gut the cats on an OBD-II vehicle you must install a MIL-eliminator on the downstream sensor. The upstream sensors MUST remain functional regardless of OBD-II or not.
With or without cats, the EFI system requires that ALL upstream HEGO sensors remain functional. On 96-up vehicles with OBD-II there is a downstream HEGO sensor between the cats and the muffler. If you gut the cats on an OBD-II vehicle you must install a MIL-eliminator on the downstream sensor. The upstream sensors MUST remain functional regardless of OBD-II or not.
Senior Member
Joined: Jul 2006
Posts: 201
Likes: 1
From: Devol, OK
Originally Posted by selbona
I read your post. I can't figure out what your mileage actually is now. I think we've got the same set up. 302, 5 spd. I've still got the stock 3.55 ratio. What do you think you get per gallon, just normal driving around. Also, have you got the stock manifolds still on or headers?
stock manifolds
3.31 ratio differential
Last edited by Radio; Nov 20, 2007 at 02:49 AM.
There will be no problems if you cut the cats off. The o2 sensor is before the cats so you don't have to worry about that. The later model trucks have one after the cat to see if they are working right.
