removing the o2 sensor...

[fordguy64]

ok well im not sure if this is the correct area for this queston so if its not sorry...

ok well i have a 1996 4.0 5 speed it has the dual cats and an o2 sensor after that cat... i want to redo my exhaust and remove the cats.. so my question is is there any way to trick the computer into thinking the o2 sensor is still there and reading correctly?

Thanks
Rob

 

[Robin Hood]

ok well im not sure if this is the correct area for this queston so if its not sorry...

ok well i have a 1996 4.0 5 speed it has the dual cats and an o2 sensor after that cat... i want to redo my exhaust and remove the cats.. so my question is is there any way to trick the computer into thinking the o2 sensor is still there and reading correctly?

Thanks
Rob

theres no point.

leave it how it is and use the sensors. without them the truck will go bananas and not know how much fuel to put in. sensors help the truck run with maximum efficiency and power.

 

[fordguy64]

if i left the o2 sensor there ans removed the cats would that be ok? im re doing the suspension and i dont really have room for the cats lol

 

[Hahnsb2]

No it will not be, without cats and OBDII truck will run like shit.

 

[mudnsnow]

The o2 sensor upstream of the cat are used by the computer to adjust the air/fuel mixture. The o2 downstream of the cat are used by the computer to verify if the cat do is job. So you can remove the cat and the downstream o2 sensor and your engine will run fine, but you will not pass emmision test(and reject more harmfull gases into atmosphere), CEL will be always ON.

 

[fordguy64]

the cel is on anyways... the egr valve... another thing on the list...

 

[Robin Hood]

Well, the truck will be thinking its running rich, so it will run extremely lean and it won't be any fun....

So you kinda have to leave it.

 

[aggoodin]

The o2 sensor upstream of the cat are used by the computer to adjust the air/fuel mixture. The o2 downstream of the cat are used by the computer to verify if the cat do is job. So you can remove the cat and the downstream o2 sensor and your engine will run fine, but you will not pass emmision test(and reject more harmfull gases into atmosphere), CEL will be always ON.

This is exactly right. If you can stand the CEL you can leave the cats out and the sensors in. The first o2 sensor adjusts the mixture and the second is looking for a difference from the first to verify a working cat.

I ran no cats on an 02 Mitsubishi Lancer for years, the only things that happened was the smell and the heat coming out of the tailpipe is pretty nasty without cats, it burned the paint around the bumper opening in the back. My mileage was up to 32mpgs.

 

[rangerbert]

I used to have a 93 5.0 mustang factory headers, straight H pipe flowmaster mufflers O2 sensors in the straight H pipe the mustang ran fine. When I needed to get it to pass emissions I put the cats back on.

 

[aggoodin]

The Honda folks take and put a spark plug spacer that has the same threads as the o2 sensor on the 2nd sensor. This pulls it back out of the pipe and changes its exposure to the heat and makes it read different than the first sensor and fools the computer into thinking there is a cat in between.