i have been debating for a while now if i want to do (true) dual exhaust.
a coworker and i were talking about it this morning and he showed me his f150 and what he did. he cut the y pipe off and inserted a straight peice in on the passenger side and ran the driverside parallel to the passengers. but on the drivers side he just ran a pipe without any o2 sensors. and on the passengers side is where both of the o2 sensors are. and he has never had a code show.
so my question is.
do o2 sensors read the air fuel mixture in the exhaust and adjust the fuel air mixture accordingly?
or does it read the exhaust temp? and adjust the fuel air mix that way?
if it reads temp, then couldnt i do the same thing and cut out the y on the pipe and run another pipe with a cat and a muffler on the drivers side like he did? or are ford o2 sensors different form dodge?

 

http://auto.howstuffworks.com/question257.htm

 

so i read all of that, but i still dont understand completely. it doesnt let me know if i can or cant do what i want. is it possible that i just double up on my o2 sensors. a set on each side and just splice the o2 sensors together. like hook both up stream together and both down stream together.

 

oxygen sensors read the makeup of the gas flowing through the exhaust pipe, how much oxygen, how much unburnt fuel ect, based on this information a voltage is put out to the PCM which tells it too rich or too lean and the PCM adjusts.

in practice the truck will still run the way that your friend has it set up, but it will only monitor 1 (ONE) bank of cylinders so it will likely not run well unless you have two pre-cat sensors (one on each side)

 

ok so i need 2 pre cat sensors 2 sets of cats and if i want 2 sets of after cat sensors. but how do i connect them?
is there a specific kit i need to buy to hook it up? and a chip?
or do i just splice the 2 sets of sensors together?
i would really like to have true dual 2.5" exhaust. that would sound b!t(h!n.

 

I'm looking into the same dual exhaust set-up myself. For optimum performance you would want O2's in each bank, however the standard PCM doesn't allow for dual O2's. According to what I can see in the wiring diagrams, the 5.9L PCM connector 1 pins 24 and 25 are O2's 1/1 and 1/2 respectively. In the 4.7L California PCM 24 and 25 are the same but pins 26 and 29 are labeled for O2's 2/1 and 2/2. There is no California listing for a 5.9L.
Looking at the connector pinout for C1 on the 5.9L nothing is listed for pins 26 and 29. This leads me to believe that the 5.9 PCM is not capable of monitoring dual O2's...or it is and there is some aftermarket programming to be done. I'm still looking into it and will post any info I can find.

 

afaik the 98-00 vehicles all came with no more than 2 sensors and cannot have them added)definitely not easily)

 

I absolutely agree with you shrps. The 5.9 was never intended to have dual exhaust.

However,

Looking into this further I have noticed something. All of the PCM pin-outs for all of the engines are identical. The only differences involve the “not connected” points, ie…coil driver #3 on the 4.7 where on the 5.9 it shows nothing connected. This leads me to wonder if the same PCM was used in all models with the only difference being the program loaded into it.
Before you shake your head, consider this: the 3.9L, 5.2L and 5.9L all use the same C1 pin-outs. The 4.7L connector has the same pin-outs where they are common. If a manufacturer were going to mass produce X number of each engine/drive train, three of which use the same pin-out configuration, and one that is damn close, wouldn’t it make sense to simply mass produce the same PCM and adapt it for each system via programming?
Hey, maybe I’m wrong here, but it’s worth thinking about. The problem is finding an aftermarket program…if one exists.

 

i know that the programs in the PCMs are different, are the chips, idk i know that the 4.7 controller changed mid year 2002 from a 3 connector unit to a 4 connector one, so in 2002(part of) and 2003 the 4.7 and 5.9 definitely used different PCM hardware, the rest of the years idk.

that said the 5.2 and 5.9 were the only options available in 1998, and they did not have options for the 2nd sensors, so if you wanted to run duals you would only be monitoring one bank of cylinders.

 

ok but any ways the way its set up now the pre cat and after cat sensors monitor both banks. its not like it is able to tell you if one side or the other is the problem you have to find that out for your self. but if you knew that you had a solid new or rebuilt or buit up motor, you wouldnt have to worry about any problems especially if you had new injectors and plugs wires etc... so i guess im going to give it a shot and do the true dual when i do my motor swap. ill try to do a H pipe configuration like on a fox body mustang gt. but seeing as how both pipes will be running close to each other ill see how it goes and ill start a new thread and post my findings. and maybe it will be the next "big thing" !