5.0L Exhaust

[410Fortune]

Can you guys please confirm this is basically the setup on a 5.0L equipped Explorer:

Sorry its hard to see.
I need to confirm I can ditch the resonators and run a Y pipe from there to a single 3" Exhaust.

 

[302Xplorer]

Mine had a single resonator after the muffler, but the rest was the same as the picture.

 

[410Fortune]

so an additional resonator after the muffler, along with the two I have shown in front?

 

[302Xplorer]

Sorry bad description.

2cats into 2 inlet muffler to single outlet to single res. to pipe out the back.

 

[section525]

Yeah.. my '99 is the same as what 302Xplorer is saying. Don't know if the '96 has the resonator(s) before the muffler. I had a cat-back put on before I knew what exhaust was.

 

[TheJMan]

Mine's got 4 catalytic converters with one resonator after the muffler. Change the dual resonators part on the pic to cats, and add a small resonator after the muffler and that would be the setup.

 

[410Fortune]

but the 02 sensors are before and after the cats, correct? I plan to ditch everything after the 02 cataylist monitors on my BII, am I missing something here?

what I have labeled as dual resonators, are those secondary cat converters? Because thats what I thought when I first looked at them, but I couldnt understand why the 02 sensors would be in front of the larger cat converters.

I am keeping the cats to be legal and the 02s to let it run right, after that I want y pipe into single 3" muffler and pipe, thats it

 

[V8BoatBuilder]

Jamie, I've modified your diagram to relflect the exhaust on my truck:

The post-cat O2 sensors are at random locations in the pipe, the driver's side is much further away from the cat than on the passenger side.

The second set of cats is not monitored.

 

[410Fortune]

Nice work! I know its not an exact diagram, my question for you then is do I still need the rear mounted cat converters? or just the ones in the down pipes?

 

[V8BoatBuilder]

The rear cats are 'optional' in the sense that they:
1) Are not monitored, and won't effect the PCM.
2) They are "converting" exhaust that has already been "converted." It's like rinsing your laundry twice. Sure, the output from the truck will be cleaner, but if the primary cats are working fine, then theory would dictate that the secondaries won't be contributing much. I could be wrong on this, as the Explorers are not the only vehicles with dual in-line cats.
3) However, most vehicles only have one cat per bank.

 

[410Fortune]

thats what I thought just wanted to confirm, they are going to be disposed of propoerly dont worry, but nothing extra is going on my truck...

 

[V8BoatBuilder]

If I ever have to re-do my exhaust, from the headers back, I will only be having two cats (one per bank).

 

[SilverBullet]

Would it be illegal to remove two of the four? MD does a visual inspection usually to see if they are there. I wonder if the inspection tech would notice that there would be two high flow cats instead of four.

 

[410Fortune]

Should not be illegal, but I would check first.
one aftermarket cat qualifies for two factory ones, your local exhaust guys should know

 

[eckerta82]

any specifics on where the first 02 sensors should be placed? going to weld up a bung in there myself, so i guess i need some distances. I know some people have said the distance front the headers is critical

 

[Nitrous SSC]

I cut the rear cat off my V8 SHO where it y-'d from each manifold. Never had any problems passing the sniffler.

When I decide to dip into my explorer's exhaust I'm going all out.

Torque Monster headers to custom 2.5" piping with 2 highflow cats to an X pipe to 2 sideways mounted dynomax's and have the 2 pipes run side by side out the back to the factory location. I dunno if it will fit but I know at least one of each of thoes things have been done on a 5.0 X.

I can't stand the bend in the exhaust midpipe just after the passanger side header flange. I've socked that on so many rocks, and I know that bend hurts flow big time.

 

[briwayjones]

Would it be illegal to remove two of the four? MD does a visual inspection usually to see if they are there. I wonder if the inspection tech would notice that there would be two high flow cats instead of four.

Really? They've never done a visual inpection whenever I've gone in. Depending on the year they either just put the pipe at the exhuast pipe and ran it on the treadmill or just hooked up a monitor the the PCM.