The Header No Cats CEL Blocker Write-Up

[Jus14]

Well as all of you know without the cats in place on the Versa and the OBX header and downpipe set-up,you will indeed get a CEL light...

Tools You Will Need:22mm wrenchVise GripsDrill or Drill Press Preferrably1/2" Drill BitJack and StandsHelp! Brand Spark Plug Non-Foulers Pack of 2 Part #42009Patience Most of All

Start by jacking the car up get it on stands,to access the header if your header is already on as mine was you have plenty of room for your hands,but hard to get the O2 sensor off that is where my vise grips come in lightly clamp them on the senor and loosen it up and take it out because of the shape and funny ring around the sensor you cant get a wrench on it unless you cut it off i left mine in place,once you have the sensor off you ready to build your non-fouler set-up....

Take 1 of the 2 non foulers and drill it straight through be careful not to buger the threads this one will be the one directly on the sensor yet again because on the longer style and shape of it so it will fit over the sensor...

Test fit them together so it will be far enough out to bring it out of the exhaust flow enough to not shoot off a CEL ,they also cam with washer like ring use them also between your 2 non foulers before you put them together...

Now it should look something like pictured below,besides the non foulers mine are together but the drilled out one as i said goes directly on the sensor,i was just test fitting everything over and over....Good Luck hope This Helps

[Jus14]

TTTAAAAADDDDDDAAAAAAAAA!!!!!!!!! HAHAHA

[reyes1212]

Nice!Did you notice a change in sound?I want to do this as well. How much did it cost to install it?

On the write-up, I got confused on what you meant to do on the foulers. We just drill into the center of just one of them and then screw them together, also screw them into the hole where the O2 sensor was, and then finally screw the O2 sensor on them like in the final picture?

[Jus14]

Yeah you got it .....and i think the 2 non foulers were 5 $ so thats all it cost me but i think im going to do my second sensor to be sure also it dont read to much back pressure.

[superskunk]

i dont have the time or the patience to do this myself... if i paid you would make and send me a pair?

[#1Tango]

you didn't do the 2nd sensor? why would you need to do the first one on the header? i mean if you didn't put foulers on the downpipe with no cat the you will throw a CEL but will you throw a CEL if just by replacing the header itself? i think im confusing everyone on my post. im only saying this because i have a CEL but i think that is because my header and my exhaust bolts busted apart and i was riding around fora while with just the header leaving the 2nd sensor exposed.

i thought it was more necessary to have foulers on the 2nd sensor rather than the 1st. what is the reason for having the foulers on the 1st sensor. im just confused

[Jus14]

Well the way the engine light is detected by the first is air/fuel mixture to not enough gas flow will dump fuel all over it to much flow will start leaning it a little more and yes both would be advised because the second is what controls back pressure which would also set it off showing to much or not enough flow......also if you want i guess i could make you guys some for price of the non foulers and a few bucks if interested.....i will post when i get the second one installed

[#1Tango]

hmmm i didn't know that. maybe thats y i am throwing a CEL? but ive had it installed for quite sometime now... maybe it takes a while for the car to turn the CEL on. has your CEL turned off from installing just the 1st one? plus these days, the CATs are pretty free flowing and don't restrict, so back pressure won't come from the CATs but just from the diameter of your exhaust.
Modified by #1Tango at 9:59 AM 3/24/2009

[superskunk]

still no CEL from mine at all!

[reyes1212]

I want thisssssss

[Jus14]

superskunk.....do you have both sensors done also? mine hasnt got one yet from just the first one done......but still want to do second one

[#1Tango]

he doesn't have sensors on the 1st or 2nd one, and hes not throwing a CEL. im sure the only one you would throw a CEL on would be the 2nd

[#1Tango]

how did you get the o2 sensor off exactly? did you use the vise grips on the silver part? or the gold part?

[robj80]

Now I'm not positive exactly how the 1.8 V is set up but normally you only need the fouler on the down stream O2 behind the cat. I would not put one on the upstream O2 as this is what affects your air fuel. It probably won't hurt you because even if it affects the A/F your ECU will compensate. The rear O2's just need to see a slight difference in the reading. I never heard of an O2 reading backpressure? Maybe it's a new thing but I don't see how an O2 can do this.

[biggie]

how did you get the o2 sensor off exactly? did you use the vise grips on the silver part? or the gold part?

Usually an adjustable wrench is used on the silver part.

[#1Tango]

Usually an adjustable wrench is used on the silver part.

thanks, figured it out