exhaust question

[jmonger]

Hey guys,
Its me again, So I have my truck at the custom exhaust shop and im stuck on what to tell the guy I was hoping that you could help me out. Its an o2 sensor plug hanging down on the drivers side near the header and there are three plugs on top of the trans, two blue and one gray I dont know what they go to. I wanted to know what you guys have been doing to keep that check engine light from coming on. If you dont already know i've got a 99 ranger with an 01 exporer 5.0 with torque monster headers and a 4r70w trans with the ranger electric transfer case. I did not have the donor explorer so I can't tell where the plugs on the trans went on the exhaust. Also do you guys just run the pipes out in front of the passenger side rear tire or do something different? If you can, post me some pics and some info about this I want it to sound good and pass inspection. I was thinking about Y piping from the headers to 1 cat then going into 1 big flowmaster then coming out with 2 pipes and right out in front of the passenger side rear tire, but I dont know anything about the sensors.

 

[85_Ranger4x4]

I ran mine out the back coming down from above the frame behind each tire... you have to have a bodylift to play that game though.

 

[Got302ci]

The blue connectors are for pre cat sensors, you need those!! Grey are post cat, leave them empty and have someone write a tune for your PCM that deletes the cat monitor O2 sensors, that's what I did anyway but I also do not run any cats and I have no emissions testing in my state (MN)

 

[jmonger]

what about the one right behind the engine I think its gray do I keep that one?

 

[Riq21]

The 02 sensors need to be handled as stated above. I ran my exhaust off factory exhaust manifolds to the mini cats on each side, then to 2 in, 2 out magnaflow muffler and then exit to just in front of passenger rear tire. Capped with 3 inch slash cut stainless steel covers.

 

[jmonger]

ok im going to the parts store and picking up the up stream 02 sensors one is $78 and the other is $55 But I dont know what side or where to put them on so I hope one of you guys can tell me. I guess the one right behind the drivers side header is getting deleted out in the program along with the one gray one on top of the trans

 

[RangerSVT]

You should have 3 o2 sensors, 2 blue (pre cat, near manifolds/headers), 1 for each bank, and one grey for post cat(after catalytic converters). The grey can be deleted with tune, but you need both blue sensors...

SVT

 

[V8 Level II]

Your Explorer 5.0 originally used a total of 4 oxygen sensors, 1 upstream and 1 downstream in each of the 2 banks. Upstream = before all cats. Downstream = after the small light off cats.

The GRAY upstream connectors are for the oxygen sensors that perform the bulk of the fuel control. The downstream BLUE connectors are primarily for OBDII cat efficiency monitoring.

Engine harness:

Driver side (bank 2) upstream - fuel control
Gray connector shell
Red/Black wire

Transmission harness:

Passenger side (bank 1) upstream - fuel control
Gray connector shell
Gray/light blue wire

Driver side (bank 2) downstream - cat monitor
Blue connector shell
Violet/light green wire

Passenger side (bank 1) downstream - cat monitor
Blue connector shell
Red/light green wire


[Each connector has a total of 4 wires. I have listed one unique color code in each connector for identification purposes.]

 

[jmonger]

so do I need all 4 or can I delete two of them? Which ones can I delete Im hearing two different things. It looks to me like rwenzing is right in my case because there is a gray plug case hanging right behind the drivers side header so there is no way that this is down stream.

 

[V8 Level II]

For fuel injection feedback control, you only need the 2 upstream O2's.

To keep the Catalyst Efficiency Monitor of the factory OBDII diagnostic system, you would also need the two downstream O2's and the two small cats in good condition. If you have a flash tuner like SCT or similar, it may also be possible to turn off the Cat Monitor in software.

 

[RangerSVT]

Rwenzing is correct. I always get those backwards. Thanks for chiming in

SVT