I am doing longtubes w/ off road pipe soon and I bought the headers without the O2 fittings because I planned on getting my computer programmed to delete emissions and the O2 sensors. I guess Im a little confused as to what exactly they do (the O2s). Is it a bad idea to get rid of them? If so, how would I go about putting them on without the fittings on the headers? Could I put them on the y-pipe? My mods are just bolt-ons and an NX 100 shot.

 

There were 4 sensors on your 96 when it left the factory.... one in front of each cat, one after each cat. The after-cat sensors are just there to monitor cat efficiency. You can program them out, or use "simms".

The pre-cat sensors are not just for "emissions".... they totally control the A/F ratio, and allow the PCM to adapt to modifications and changing driving conditions. You can delete them, and force the PCM to operate constantly in "open loop". Unless you find one hell of a tuner, you will probably lose fuel efficiency (MPG) and could start fouling plugs. And you will need to revisit that tuner every time you change something on the engine.

The pre-cat sensors need "bungs", welded into the header collectors, as close to the point where the 4 tubes merge. If the sensors don't reach the correct operating temperature, because they are too far from the engine, you will have problems.

 

The O2 sensors are used by the computer to measure the Air/Fuel ratio so it can decide how much fuel to add to the cylinders. Without them, the computer won't be able to manage the tune of the engine correctly. You can't delete them - it'd be kind of like just deciding you'd like to run the engine without spark plugs.

Where they are positioned is fairly important, as they need to be close enough to the heads to heat up well enough. Whether they must be in the headers or can be in the y-pipe, I'm not sure. Maybe someone who's done that with LT's can offer up a suggestion.

Dave

 

aaarrrggghhh!... Thanks for the quick response. I am not sure what to do now. Any suggestions are appreciated ...

 

Need to be in the headers...putting them in the Y-pipe would work for the o2's that come after the cats, but simms or programming work just fine as well.

I do believe if you ordered headers without the 02 bungs, you can do it yourself or have someone who knows how....not exactly sure about this....can anyone else help him on this?

 

A muffler shop should be able to weld a couple of bungs on for you pretty easily. Shouldn't be a problem.

 

thanks very much guys

 

For what its worth, I have JH LTs without O2 bungs and I put O2 bungs in my header muffler after the collector.
Goes into closed loop fine and my scanner looks good.
I used Bosch O2s and extended the wires on the sensor, both no nos according to the board.
Maybe I am just lucky or maybe I need a more long term test to see if this holds up.
Just my expeirences so far.
Good luck.

 

How much critical is the installation distance? I know these sensors have a heating element to bring them to operating temps. I've fixed mine in the y-pipe just after the header flange, but if that's to far I can fix them to the collector which whould only be less than 1' closer to the engine.