Ok here is a pic. best I could do it's all the further I could get under the hog.

 

In some states, the presence of a lit SES light is enough to fail one for emissions testing. CA, and WA come to mind. I'm sure other states as well.

For $2.50, it's cheap insurance. You have to have a puckered tight hole to not want to try this mod.

 

I just took it threw emmisions with it and was all good. so it works.

 

yeah but for 5 bucks you don't have to have that god damn light driven ya crazy.

 

so you removed your cats? I am still haveing a hard time with this one....if that rear O2 does not read within its set criteria then it will set a code at some point...maybe not now, not in a week....but it will.

 

I understand what you are sayin but like I said we did it on my buddy's car a couple weeks ago and he has no ses light.So it must be reading something it likes. I have had them since saterday, no cats just with these defoulers, no light. If it does go off I will let you all know but it hasn't yet and I have prolly put over 150 miles on the truck since saterday. So thats all I can really say to ya. If it does set a light I will let ya know, but if not you can save a coulple of bucks.

 

so then plug em back in - drive around - no light - pass test

 

true
Ive got hp tuners now and I just deleted all that stuff. Tuners is the best mod Ive done to this truck it has taught me the most.
Here's one for HP tuners

 

Well you know that an oxygen sensor works by reacting to the oxygen content in the exhaust stream and converts that to a voltage right? Being post catalytic, it's a 1V sensor IIRC, much like the Autometer light show gauges

When you have unburnt fuel, your going to have a voltage less then .5V, and when running lean where there is more oxygen, you'll be over .5V generally speaking. exact figures are rounded up to protect the innocent.

So by placing the sensor out of the main stream, it'll receive a smaller sampling of the gasses, thus no SES light. There is really no "it will come on eventually." Your in effect physically crippling the sensor to now only work with say within a smaller voltage range, say about 3-.7V which is well within factory computer specs.

Your factory computer looks at the sensor and at start up will see about .5V (it's actually .45) But at around 300 degrees C where the sensor is working at it's operating temp, that .5V will fluctuate, and tell the computer that it's ready and working. If that test passes, with the voltage varying up and down, then to the computer the sensor is working.

Where can one go wrong with this? If the sensor it too far from the stream to not heat up, then you may get a light. Other then that, it's a 90+% chance this will work for most.

 

I am pretty aware of how the O2's work.....I am not saying it is a bad idea to try.....I am saying that it will set a code sooner or later.