O2 Sensor modification using spark plug non-foulers

[Aaron]

o2 sensor points

The more I learn the more I realize I don't know. I like to take this stance too.

I understand the oxygen influence in a very basic way in relation to the o2 sensor. Little oxygen = rich so it leans the mixture out. Lots of oxygen = lean so it richens the mixture up.

I don't understand the temperature connection very well except that it seems that it needs to be at "normal" operating temp to do its job.

The non-fouler mod will definitely reduce the amount of oxygen getting to the sensor to lean it out. However, the spacer will also most likely reduce the temperature of the sensor as well so how does this really effect it?

Less oxygen so it will lean the mixture using less gas but lower temp will richen back up and break even so no point? That is the two things I see here in conflict with this modification potentially.

Everything I read about this sensor mod is for the 2nd o2 sensor with removal of the catalytic converter, etc... and not for fuel mileage increase. Just that hydrogen website selling the non-foulers as a solution for what I want to accomplish with it...keep the mixture leaner.

The temp thing may be further complicated with the RXP Generation II additive because it causes the exhaust to be lower anyway because of radiant containment methodology and more thorough burning so less heat & less emissions.

If I need more heat in the sensor, I will add my nasa ceramic paint additive to some high temp paint and paint it on the non-fouler spacers and the outside of the o2 sensor and that WILL lock in more temp.

A steam pipe at 400 degrees outside temp dropped to 200 just by being painted with the ceramic additive so this is what I will do if necessary.

No matter what is supposed to happen, often it becomes apparent that real world experience sometimes contradicts what we think will happen and this makes it necessary to actually do the experiment.

After I get through a few tanks, I'll know if I'm using more or less gas and that should answer the fuel mixture question if it does what is supposed to happen. If there is pre-detonation that is undetectable by sound, etc..., I'm sure I can tell by looking at the plugs to see if there is evidence of that. I have NOT looked at the plugs currently to even be able to compare but I may.

Also, the 14.7:1 mixture is also an ideal mixture for a simple spark as far as I understand. With a true burst of plasma like Firestorm plugs, there is enough energy there to fully combust a lean mixture up to 40:1 for practical use and even 100:1 for demo purposes...so it also has to take in to account what is contributing to the release of the mixture lean or not.

[Redmeanie]

O2 Sensor Temp

You are right Aaron,
The O2 sensor just needs to heat up to "Operating" Temp....It does not calibrate only according to the temp of the exhaust.... I was just stating that hotter exhaust = a lean mixture and cooler exhaust = a rich mixture to a post left by someone else. I know this from toying around with Turbo cars for awhile.

So don't worry about the "Temp" with the spacers it will certainly get to its proper operating temp and function properly. It just wont see as much O2.

[Redmeanie]

O2 Info .....For your enjoyment!

Info on O2 sensors from wikipedia.....Also how stuff works:

If you read through this little bit you will see that the O2 measures, well exactly what it says O2, then compares it with O2 going into the engine.

Temp "of the sensor" has little to do with it except to make sure its at it's operating temp so the readings are accurate.

Automotive applications

Automotive oxygen sensors, colloquially known as an O2 sensors or lambda sensors make modern electronic fuel injection and emission control possible. They determine if the air/fuel ratio exiting a gas-combustion engine is rich(unburnt fuel vapor) or lean(excess oxygen). Closed loop feedback controlled fuel injection means that the fuel injector output is varied according to real-time sensor data rather than operating with a predetermined fuel map (open loop). In addition to improving overall engine operation, they reduce the amounts of both unburnt fuel and oxides of nitrogen from entering the atmosphere. Unburnt fuel is pollution in the form of air born hydrocarbons, while oxides of nitrogen(NOX gases) are a result of excess air in the fuel mixture resulting in smog and acid rain producing compounds.

This information is sent to the engine management ECU computer, which adjusts the mixture to give the engine the best possible fuel economy and lowest possible exhaust emissions. Failure of these sensors, either through normal aging, the use of leaded fuels, or due to fuel contamination with eg. silicones or silicates, can lead to damage of an automobile's catalytic converter and expensive repairs.

Tampering with or modifying the signal that the oxygen sensor sends to the engine computer can be detrimental. When the engine is under low-load conditions (such as when accelerating very gently, or maintaining a constant speed), the engine is operating under 'closed-loop mode'. This refers to a feedback loop between the fuel injectors, and the oxygen sensor, to maintain stoichiometric ratio. If modifications cause the mixture to run lean, there will be a slight increase in fuel economy, but with massive nitrogen oxide emissions, and the risk of damaging the engine due to detonation and excessively high exhaust gas temperatures. If modifications cause the mixture to run rich, then there will be a slight increase in power, again at the risk of overheating and igniting the catalytic converter, while decreasing fuel economy and increasing hydrocarbon emissions.

When an internal combustion engine is under high load (such as when using wide-open throttle) the oxygen sensor no longer operates (it works, but the signal isn't used to make adjustments in relation to fuel trim/control), and the engine automatically enriches the mixture to protect the engine. Any changes in the sensor output will be ignored in this state, while changes from the air flow meter can lower engine performance due to the mixture being too rich or too lean, and increase the risk of engine damage due to detonation if the mixture is too lean.

[edit] Function of a lambda probe

Lambda probes are used to reduce vehicle emissions, by ensuring that engines burn their fuel efficiently and cleanly. Robert Bosch GmbH introduced the first automotive lambda probe in 1976, and it was first used by Volvo and Saab in that year. The sensors were introduced in the US from about 1980, and were required on all models of cars in many countries in Europe in 1993.

By measuring the proportion of oxygen in the remaining exhaust gas, and by knowing the volume and temperature of the air entering the cylinders amongst other things, an ECU can use look-up tables to determine the amount of fuel required to burn at the stoichiometric ratio (14.7:1 air:fuel by mass for gasoline) to ensure complete combustion.

[edit] The probe

The sensor element is a ceramic cylinder plated inside and out with porous platinum electrodes; the whole assembly is protected by a metal gauze. It operates by measuring the difference in oxygen between the exhaust gas and the external air, and generates a voltage or changes its resistance depending on the difference between the two. The sensors only work effectively when heated to approximately 300°C, so most newer lambda probes have heating elements encased in the ceramic to bring the ceramic tip up to temperature quickly when the exhaust is cold. The probe typically has four wires attached to it: two for the lambda output, and two for the heater power, although some automakers use a common ground for the sensor element and heaters, resulting in three wires. Earlier non-electrically-heater sensors had one or two wires.

The whole article is here:Oxygen sensor - Wikipedia, the free encyclopedia

[chewysdad]

I'm rebuilding a Jeep 4.0l engine for a Cherokee. I have put Singh Grooves in the head as there are significant mileage improvement claims made for them. SOMENDER-SINGH.com - Home The grooves reduce exhaust temperature and allow the engine to run leaner, but the ECM of a modern engine compensates by adding more fuel because of the O2 sensor. Hence, the quest to fool the O2 sensor which lead me here. My concern is how do you prevent too lean a mixture which can burn up the exhaust valves. If you've ridden in a small plane, the pilot will lean the engine fuel mixture at cruise and use an exhaust gas temperature gauge to do the adjusting. It seems it may do well to have two O2 sensors, one normal and the other "spaced out" (sorry I grew up in the 60's, couldn't resist). With the two sensors you could choose a proportion of each and adjust the mixture, maybe with a potenteometer like choosing more trebel or bass on a stereo. All the way one way would be full lean, all the way the other would be full normal. It may be good to have an EGT gauge to monitor what is going on. I'd hate to spend $1,000 on an engine kit and machine shop work and then go out and burn up the valves. This site is great!
I'm also curious about the PULSTAR plugs. They may be best utilized if the engine timing were retarded some. Once again, how do you change the ECM? On the Jeep I may be abe to shift the CPS-crankshaft position sensor-some as it is mounted on the bell housing, an adjustment of 5 degrees may be possible. - Scott, Chewy's dad.

[chewysdad]

Hello again! I remembered, low voltage is lean, high voltage is rich, so simply adding a resistance to the output of the "spaced out" O2 sensor would allow you to enrich the mixture if desired. If what is stated above is correct, moving the sensor out of the exhaust stream will increase the sensor output voltage causing the ECM to lean the mixture in attempt to bring the voltage down. Adding a restance in line would bring the voltage down and the ECM wouldn't lean the mixture as much or at all depending on the amount of resistance. Maybe one of the double Es out there can work up a simple pot plus resistor circuit for us. I believe this is correct because till now fancy circuits were created to add to the O2 output to make the voltage higher so the ECM would lean the mixture. Then we need an inexpensive EGT setup. - Scott

[Aaron]

electronic circuits for o2 sensor modification

Here are 3 electrical circuits for fooling the computer o2 sensor readings:

http://www.mkiv.com/techarticles/oxy...sor_simulator/

Electronic Fuel Injection Enhancer Manual (EFIE) [4901.99.00.503] - $9.00 : Eagle-Research Store

http://better-mileage.com/memberadx.html

I was going to build the Eagle Research circuit but did the non-fouler mod because it is simpler and less expensive. Maybe it works better and more specific and maybe there is a benefit to both.

[chewysdad]

Thanks, I hadn't seen the first one which simulates the O2 sensor, the other two I have seen. They are the circuits I mentioned above that ADD a voltage to the O2 sensor output to lean out the mixture. Neither of the latter are what you would want if using the antifouling spacer. These and their complexity are what the spacer allows you to avoid. - Scott

[Redmeanie]

Interesting Tidbit....

I have been reading in depth any and all info I can find on the O2 sensor and I ran across this interesting side note:

By modifying the O2 position as we are doing here instead of modifying the electronics, under full throttle or heavy load the ecm resorts back to its factory settings and does not use the O2 sensor to calibrate the A/F Ratio.....This is great for our intentions because with a "Booster" or other After Market Mileage Increasing add ons we would not have to worry about the Engine suddenly going to a too lean state. When it resorts back to factory programed settings it is in "Rich" mode until the load or full throttle requirements are relieved.

[chewysdad]

That's a great tidbit! I'll do some searching to verify. Not because I don't believe you, just my nature. The information superhighway! I'm constantly amazed! The information on this site is amazing! Thanks!

[Aaron]

vacuum in non-fouler cavity?

Just an observation, but with this modification, wouldn't the venturi effect create a vaccum in the little non-fouler where the probe is... in that cavity would be negative pressure sucked out by the high pressure exhaust blowing past it right?

That would not only ensure less oxygen if this is the case, but there will probably be no carbon buildup inside at all.

Any comments?

[Redmeanie]

I was Thinking Kinda the same thing.....

Aaron,
I was thinking something along those lines also....The Venturi comparison is the perfect way to put it also! That is probably exactly what is going on here, and in that case it would kind of be throttle responsive. Where at idle it would cut fuel but not as much as when cruising at say, Highway speeds.... If that is what is really happening, that would be "Too" Great!

[chewysdad]

I'm only assuming, but I believe the O2 sensor must be a sealed unit or close to it or it would present an exhaust gas leak in it's stock configuration. The exhaust gasses in the exhaust pipe traveling past an opening in the side of the pipe would create a pressure drop around the O2 sensor set back in the anti-fouling extension, but I don't see it having any effect.

[Redmeanie]

Hmmm...You could have something there

Perhaps we wouldn't get a full vacuum in the Fouler assembly.....Maybe the exhaust would just go "The Least Resistance Way" and blow right by the small opening in the fouler assembly, especially once the pressure inside is at least equal to the exhaust going by..... maybe just circulating the air inside the assembly slightly.....Just enough so the lightest gas molecules do not accumulate inside the assembly?

[Aaron]

o2 sensor mod is sealed with no leaks

With the double non-fouler mod, it is 100% sealed and there are absolutely no leaks.

Here are the 2 non-foulers on the sensor:


Here it is on the manifold:


As exhaust gas rushes past, the only hole the exhaust gases go by is the hole in the bottom of the non-fouler that is plugged into the manifold. Past that hole, there is the opening of the 1st non-fouler with the tip of the o2 sensor and past that, it is 100% totally sealed. There are zero leaks.

Maybe I misunderstood the comments, but the unit is sealed so based on this, there should be low pressure around the o2 sensor probe.

As far as any effects, I'm just thinking that the exhaust gases rushing past will not be able to really push any oxygen into there since the exhaust gas rushing past will suck anything out of the sealed chamber further reducing the chance of the sensor reading any oxygen at all.

[Redmeanie]

Would there be a vacuum effect?

You are right it is sealed, thats what we were saying....We were discussing rather the "Venturi" effect would occur inside the assembly or would the exhaust simply by pass the small opening of the assembly and then only minute amounts of gases would actually cycle through the assembly itself...