True Dual Exhaust

[Road Kill]

when installing true dual exhuast does the O2 sensor need to be in both pipes? an i have a 90 and between the 2 cats there is a small pipe going up tward the vacuum harness what is this and how would i incorporate this into the dual? thanks

 

[Seabronc]

Well, the O2 sensor is required by the computer to determine how rich or lean your engine is running so it can make adjustments to fuel flow. So you could probably get away with only one. There probably isn't any way to hook up a second one to your computer anyway.

That pipe is the air inject pipe from your air pump system. If you are keeping Cats on the system, you will run that to both of them. Most likely the aftermarket cat will combine the function of the two Cats that are on there now. The combination Cat has ****** on the side of it for hooking up the air inject and generally comes with an adapter pipe to make up for the change in length. With a Cat on both sides you wil need to come up with a way to run the air inject to both. It would be a bit of work to do but definately doable.

Talk to a muffler shop about it, they may have some suggestions.

Good luck,

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[SrATEX]

i have true dual...what the shop did was the put in an "H" pipe. so it exited the headers and went into the "H" pipe then went to the back. i have only one O2 sensor which is in the bend of the right side (right as the driver sits) above the "-" part of the H pipe.

 

[Road Kill]

Well, the O2 sensor is required by the computer to determine how rich or lean your engine is running so it can make adjustments to fuel flow.  So you could probably get away with only one.  There probably isn't any way to hook up a second one to your computer anyway. 
That pipe is the air inject pipe from your air pump system.  If you are keeping Cats on the system, you will run that to both of them.  Most likely the aftermarket cat will combine the function of the two Cats that are on there now.  The combination Cat has ****** on the side of it for hooking up the air inject and generally comes with an adapter pipe to make up for the change in length.  With a Cat on both sides you wil need to come up with a way to run the air inject to both.  It would be a bit of work to do but definately doable.

Talk to a muffler shop about it, they may have some suggestions.

Good luck,

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the pipe is actually between the cats so do i need the cats with the ******

 

[Seabronc]

the pipe is actually between the cats so do i need the cats with the ******

26447[/snapback]

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I assume that you are going to trash the old exhaust system, right? If so, then the Cats you get to replace it will have to have the ****** because it combines the function of the two you have. In effect the pipe still attaches between them but they are combined into one shell. What you have now is a Three way Catalyst (TWC) seperated from a Conventional Oxidation Catalyst (COC) by a length of pipe with a ****** to hook the air pipe to, (takes a lot of space). The new one still has both these functions but contains them in a single shell.

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