ok here is what you need


1. 18mm Spark plug Non-Fouler (come in 2 per pack) you can get it in the help section of most parts stores
2. drill and 7/16 drill bit
3. 7/8th wrench or adjustable wrench
4. vise or something too hold it while you drill it

ok here is how the defouler looks mine is dirty since I just pulled it out of the car too take some pics

if you look at the defouler it will only have small hole on the one side like this


all you do isdrill it soand it shouldlook like this


you only need too drill one just make sure you make sure too get all the metal shavings out of the defouler before you install it.
Screw the drilled defouler into the non drilled one then screw that into the bung on your down pipe/cat
here is how is how it should look when your done

 

Fixed the pictures for ya. Nice write-up by the way...

 

that really works huh? still no way on how to fix it without messin with anything? and let's say something is actually wrong wiht the cat or sensor, will it still detect it or continue to "trick" the ecu?

 

it will continue to trick the cat, but theres no reason to put the trick there if you have a cat at all becasue it defeats teh purpose. and yes it will work forever

 

A thx man yeah I thought I would stop being parasite and contrubute lol

 

o i see. because i have been postin everywhere trying to get several opinions as to what the heck is wrong with my car. this is what i have. OBX header, hi flow cat, Magnaflow cat back dual exhaust. I still get that "catalyst low efficiency" code and would like to see what everyone thinks before i go out and spend money on a new cat and or sensor. thanks a lot, i love this forum lol

 

see it might work for you if it is the high flowcat that is causing the code I would try the no fouler trick ($3) if the code does not go awaythen replace the senser

 

sounds great. all i would have to do is install the nofouler trick directly into the cat correct? if so ill try to do it as soon asi can and post what happened

 

put it on the downstream 02 sensor (the one farthest from the engine) wherever it screws in

 

I did this for about 4 mths and it becomes a pain in the but cause the defoulers always come loose. For about $20 their is a little divice that goes in the wireing and does the trick. They are all over on ebay and it worked great for me!! Of course the best thing to do is what i ended up doing and paying for a obd 2 hi flow cat. then you have no probs and the engine can correctly adjust the fuel, spark and let you know if the cat is bad!!!