'96 Oxy Sensor question - advice welcomed !

[BenMar]

Hi - New here , and I've been searching the o2 sensor tips , but not found the "right" one yet . I'm building a daily driver from a wrecked 96 Explorer , with the 4.0L V-6 engine. My body is a 1953 Studebaker pickup with the same 112" wheelbase. Since I will be using the '53 Stude title and license , I can modify the exhaust system to accomplish my goals. I want to split the exhaust system to be able to have the old fashioned dual exhaust. Now on to my question : if I keep the two front oxygen sensors in place , but cut & split the "Y" pipe before the cat. converters , what negative things will happen if I pitch those two converters and the last two oxygen sensors? I'd like that neat sound from a split exhaust V-6 engine , and I want to use the turbo style mufflers on each side . My unanswered questions are in regard to keeping the PCM happy without having the last two sensors doing anything anymore ! If I simply unplug the last two sensors , and tape off the wires , going to work? Will I cause the Check Engine light to always be ON ? Thanks for any suggestions . Ben

 

[ezrider440]

sounds like an awesome project, pictures would be appreciated. however why not use the 5.0 litre motor set up , I think in the long run it will pay off. to answer your question the rear two oxygen sensors factor into the pcm's long term fuel trim settings, and if you do remove them from the system you will cause a check engine light and significantly decrease your economy, my advice would be to search around and find one of those system which deletes the oxygen sensor input from the pcm and makes it run on two, or to put the sensors in somewhere downstream on the pips

 

[Carguy3J]

The front O2 sensors (pre cat) are what the ECM uses to control engine fueling. The rear O2's (post cat) are solely to monitor catalyst efficiency. The computer compares the readings from the upstream O2 and the downstream, to measure how much "junk" the cats have removed from the exhaust stream. Not having the rear O2's and/or no Cats WILL set off a check engine light, but it will NOT affect fuel economy or engine function in any way. Yes, you can get O2 "simulators" to allow for the removal of the rear O2 sensors. The simulators plug in to the wire harness in place of the rear sensors, and sends the computer a "fake" signal, to make it seem like there is a working senor in place. However, I would recommend getting an XCal3 flash tuner, with some custom tuning from Henson Performance. In the tune, he can eliminate the rear O2 functions and related trouble codes. In addition, you will get a smoother running and more powerful engine, and a better, smoother shifting transmission. You can also have him adjust for gear ratio and tire size changes.

As for you exhaust setup, I would discourage you from having a true, independent dual setup. Two tailpipes/ exits? Fine. Two pipes/mufflers? Sure. However, I would make sure you include an H-pipe, X-pipe, or some other crossover connecting the two engine banks. This will help w/ exhaust scavenging, and even out exhaust pulses between cylinder banks. This is particularly important on a computer controlled engine. Having totally independent exhaust pipes for each side can cause rough idling (not the "good" kind), drive-ability issues, increased fuel consumption, and reduced power. Do some research on H-pipes and X-pipes, and how/why they are a good thing. The best solution may be to stick with the factory configuration of a 2-into-1 muffler (just a better flowing aftermarket one), as others have found that there is very little room under the 2nd gen Explorer chassis for two mufflers.

 

[BenMar]

Thanks - I am going to figure out the photo posting , as I do have some picts that are pretty neat. Since this 4.0L engine has only 61,000 miles on it , I think it should power this truck just fine. One odd fact : the 4.0L converts to 245 cu. in. which is the same size as Studebaker's big six engine was, and could have come in this truck ! Question - when you say to look for a system that would delete the oxy. sensor input from the PCM - I'm not familiar with what you mean. Could you explain more of what this device is ? Thanks for the ideas ! Ben

 

[BenMar]

Question for carguy3J

Thanks ! I appreciate your info very much. I have installed the X pipes on a couple Studebaker projects and the results were to make both a good sound at the tailpipe , and what seemed like a smoother running engine , especially at the lower RPM range. On this project I will have my spare tire up in the box , so I will have some xtra space underneath for the 2nd tailpipe. If I am understanding your suggestions , you think I could go with an X pipe , then custom piping to mufflers and tailpipes ? Probably get a good sound quality in the process. Could you give me a bit more info regarding Henson Performance ? Not a familiar name to me ( yet ) . Ben

 

[ranger7ltr]

Room is lacking under the Explorer for duals...

Since the fuel tank hangs down on the left side...My solution to this issue was to run the front o2 sensors and replace the front convertors since they had 170 k on them...I then ran the two pipes into an X pipe then the two pipes from the X into a pair of secondary convertors... One of these convertors had the rear o2 sensor in in as I do not have 2 rear o2 sensors...

I further ran the outlet side of the secondary cats into a dual in/ dual out Magnaflow muffler and ran the outlet pipes out the rear of the truck on the same side...I had the front pipes made so i could remove them from the X pipe with clamps if needed...

I have 2.25" piping throughout the entire system and I can feel the difference performance wise...I also used Thunderbolt Spincast high flow catalytic convertors throughout the system...

My Explorer is a 1999 Sport model with 3 o2 sensors...You are using a 96 Explorer chassis and it has 4 o2 sensors? Maybe this is a design change between 96 to 99...Your project sounds really sweet though.. Good luck with it...

Oh and oxygen sensor simulators are used to do just that; simulate the present of the o2 sensor when it is not there...There are a myriad of these available just for the searching... I have used them myself on V8 conversions and they seem to work as designed...

 

[BenMar]

Back to rangel7ltr

Appreciate the scoop ! Yep , on the '96 w/ 4.0L V-6 , there's two small cat converters. There is an o2 sensor just before the 1st one , and another sensor just after the 2nd one. Since I'm not hanging the spare tire under this chassis , I believe that space could be useful to run a left side dual pipe. As you say , I will have to stay away from that huge gas tank tho !