Does anyone know how much the tip of our oxygen sensors will stick through these spark plug non-foulers? The threads on the inside stop approximately 1/8" below the base or deck of the threads outside.

<img src=http://members.dslextreme.com/users/g35driver/o2fooler/non-fouler_side.jpg><img src=http://members.dslextreme.com/users/g35driver/o2fooler/non-fouler_inside.jpg>

 

I would like to know this also.

 

I might be able to help. I was an engineer for NGK Spark Plugs for 4 years. I took care of the Japanese manufacturers (Honda, Toyota, Nissan). I did O2 sensors, spark plugs, knock sensors, etc.

I guess my first question is....what the heck is a spark plug non-fouler? I've never heard of this. Is it designed to prevent the fouling of spark plugs? Sounds to me like an ineffectual aftermarket gimmick, but I could be wrong.

As for O2 sensors. The front O2 sensors in our cars (pre-catalytic converter) are provided by Bosch. The secondary O2 sensors (post-catalytic converter) are provided by NGK.

The concept behind the protection tubes on the end wary wildly, so their dimensions, especialy diamater, will be WAY different.

The dimensions I know of are:
Front O2 (NOTE: Estimate only): from the base of the hex to the end of the protection tube will be about 25mm.
Rear O2: From the base of the hex to the end of the protection tube will be 29mm (exact).

My guess is that each probably extends into the exhaust tube about 15~19mm.

If you're thinking of limiting the fouling of the O2 sensor by putting these anti-fouling protectors around plugs or O2 sensors, I HIGHLY recommend against it. The O2 sensor needs as much exhaust gas passing over it as possible, in order to get an accurate reading. O2 sensors only become plugged if you run leaded fuel (very BAD idea), you've deliberately made the A/F ration really rich (like 12:1), or POSSIBLY if you live in Canada, because Canadian gas has a high manganese content (causes plugging of the ceramic element inside the sensor sometimes). Otherwise, there should be no concern for you. If anything, due to not having enough exhaust gas pass over it, due to this protector, it may trip a MIL code, saying there is an exhaust leak (a guess).

The front O2 sensors on are cars are not normal O2 sensors. They are what we call UEGO or A/F sensors, and are MUCH more precise in their reading of the exhaust gas oxygen content than a normal "switching" type O2 sensor. Actually, just as an FYI, they are the same sensors that AEM sells with their A/F sensor package, for dyno tuning, only the connector is different. So, my point is, fouling is basically not an issue for O2 sensors. The usual in-car issues are breakage due to improper servicing (installation/removal), abrasion of the wires (rubbing), or undercarriage damage (stone impact, etc).

the same goes for the spark plugs in our car. Great plugs. Double-platinum from the factory (PLFR5A-11). However, if you REALLY want iridium, with a smaller diameter center electrode, then get LFR5AIX-11.

Same goes for plugs, too, I don't recommend putting these shields around the plug. If anything, it will prevent maximized burn by limiting flame front travel in the cylinder, and the vehicle will probably not burn all of the fuel, and accelerate fouling.

Not trying to be a jerk, just trying to help. Honestly, both are very much okay, and not in need of improvement in really any way. Just my $0.02.

 

My guess is he is going to use these for the secondary O2 to help lower its readings so that you will not get a CEL when the cats are removed. Theres no problem in doing that as the secondary O2 isn't used to calculate A/F.

 

This is true,

But reducing the airflow around the secondary O2 sensor will not prevent a MIL code from appearing. If the secondary O2 reads that the exhaust mixture is "too lean", which it more than likely will if it is not after a catalytic converter and exposed to open air, then it will still trip a code.
Basically, the secondary O2 sensor still needs to be able to detect exhaust gas readings, but with less CO, THC and NOx in them (purified from the catalytic converter). Without a cat, the only plausible way to prevent a MIL code in my experience is to have something simulate the secondary O2 sensor signal.

The secondary O2 sensor's sole job is to monitor catalytic converter function. Without one, it's almost impossible to prevent a MIL from appearing. Again, of course, unless you have an O2 sensor simulator. This shield will not do anything except constrict flow of exhaust gas around the sensing element. More than likely restricted flow alone is not enough to fool the system into thinking that there is still a cat. The overall exhaust gas CO, THC and NOx content have to be reduced.

The ECU is constantly comparing the number os switching cycles of the front O2 sensor to the rear O2 sensor. In theory, with a properly working cat that is purifying exhasut gas, the rear should be sending switching signals at a lower rate than the front. When the cat is bad, the switching for both the front and back will begin to match, and then the ECU knows (or thinks it knows) that the cat is bad. No purification = same switching signal rate for both sensors. therefore, MIL code.

Not trying to be argumentative, just based on my experience, I don't think this will work, but I could always be wrong.

Just my $0.02.

 

Google it, it has been done before with much success.

 

over a week and almost 3 tanks of gas and no cel!

pics are here:
<a href=http://members.dslextreme.com/users/g35driver/o2fooler/>http://members.dslextreme.com/users/g35driver/o2fooler/</a>

 

you may not need to couple the two non foulers.. but i dont wanna get under there and remove it

 

So exactly what parts do we need to buy Eldy, and where did you get them?

 

I cant belive people would do this to their cars. I think its because most people don't know how important the function of a oxygen sensor actually is. Your whole engine's functionability is based on thereadings of an O2 sensor. Running rich or lean is all dependant on what reading the O2 sensor gives. By using a silly spacer, you are limitiing those readings. Sure you might not get a cell, but think real hard as to why that may be. The O2 sensor ISNT PICKING UP The hydrogen and carbon enough to be giving the faulty reading to trip the cell. I would gladly take a silly tripped cell over hindering my cars performance and safty consistantly for the life of the car. Also God help those people that are doing this to their FI cars. Its just plain stupid.

My 2 cents

 

As you would have noticed if you read the thread, secondary O2 sensor's sole function is to monitor cat function, so tricking it will do no harm whatsoever. This mod looks more simple and cheaper than installing O2 simulator. But what do I know... I suck at anything electrical

 

And what about the primary O2 sensor, do you not use the foulers on that as well? Of coarse you do. So you cant be oblivious to the fact that the fouler will not affect the primary sensor.

Read the thread again.

 

Are you sure that secondary O2 (after cats) isn't used for A/F calculation? Thanks

04.5 coupe Service Manual about O2 sensors

 

What model number are you supposed to get on the HELP non foulers? There is 4000,4002,4004,4006,4008. I took a wild guess, and got the 4008 but it doesnt thread into the hole the test pipes have for the o2 sensor. Which one do you guys use?

 

Well Im measured the hole in the test pipe, and turns out the 4002 is the right size. Had to drive to 3 freakin Pep Boys till I finally found one that had them in stock.