O2 Sensor Eliminator

[HondaJon_imp]

Found this on the UK CB1100 website. Sparked my curiosity.

http://www.cb1100.co.uk/index.php/topic,233.0.html?PHPSESSID=410d3bc85039810dff3ca32d5cb3e815

 

[Waffa_imp]

Interesting, I wonder how it works. The plug must send a steady signal no matter what the conditions may be. Might work great at sea level, but could potentially cause some serious problems if you take a ride up a mountain.

Might be able to achieve the same effect by hooking up appropriate resistors. Would be much cheaper than buying that plug.

 

[Ack-CB11_imp]

I got one from the UK, havn't tried it yet. It's just a loop back plug with a 300 restistor wired in or something like that.

 

[Randy B]

Ohm I'm assuming. At what wattage? 1/4, 1/2, 1?
I know...nit-picking.

 

[Deanohh_imp]

Ohm I'm assuming. At what wattage? 1/4, 1/2, 1?
I know...nit-picking.

When buying the device, you're not paying the 30 bucks for the resistor, youre paying for "knowing which resistor to put in"

 

[the Ferret]

Ok all you really smart guys..what does this thing supposed to do to/ for our bikes in laymans language.

 

[Waffa_imp]

Ok all you really smart guys..what does this thing supposed to do to/ for our bikes in laymans language.

It is supposed to prevent the ECU from making changes to the air/fuel mixture while in closed loop operation. Should make for a smooth ride when you start rolling on the throttle, less jerkyness. Will probably add some HP because the bike will run closer to stoichiometric as opposed the higher ratio that emissions prefers.

Downside: Will probably wear out the cat faster. And my guess is less power at higher altitudes.

 

[AzBob_imp]

Ok all you really smart guys..what does this thing supposed to do to/ for our bikes in laymans language.

It is supposed to prevent the ECU from making changes to the air/fuel mixture while in closed loop operation. Should make for a smooth ride when you start rolling on the throttle, less jerkyness. Will probably add some HP because the bike will run closer to stoichiometric as opposed the higher ratio that emissions prefers.

Downside: Will probably wear out the cat faster. And my guess is less power at higher altitudes.

You are making a bunch of assumptions. Unless one has access to a graph of their bike's A/F ratio at all throttle openings, this device isn't really useful, IMO. What resistance is it set for? Full throttle operation at 1 bar? The ECU is constantly making changes to the A/F ratio across the rev range to smooth out harshness, compensate for the quality of the gasoline one is currently running, and whatever else the engineers found during testing. To shackle the computer like this will likely result in degraded performance.

I agree with the poster that mentioned this is an old-school method applied to modern hardware.

An additional aside, my bike doesn't exhibit any jerkiness. The throttle response is smooth and linear from idle to redline.

 

[Deanohh_imp]

My experience with this type of device is with other bikes and using a power commander. You want power commander to have full control of the fuel maps and so you want no input from the o2 sensor. When you disconnect the o2sensor, you then are operating in open loop mode, not closed loop. The adjustments being made due to the input from the o2 sensor is what closes the loop in the engine control. So you want the power commander to have full control because it will be programmed by dyno runs to produce the desired fuel mixture and completely control the fuel map and other selected parameters so you unplug the o2 sensor.... You dont want input from the sensor. But that will produce a engine fault code because of no sensor. So this device is plugged into where the o2 sensor WAS so that the ecu thinks it is still there and you don't get the engine warning light and fault code.

I suppose if the thing produced a certain voltage that mimicked the sensor reading of a certain amount too lean, then the ecu would add a amount more fuel and give you a richer mixture at all conditions, but you don't know that you always want it richer, so if that particular one is meant to be some kind of stand alone fuel controller, its probably the worst one you could get...but the cheapest.

 

[the Ferret]

Wow, this stuff is really complicated today. I know how to make carbs work. This stuff is way beyond my comprehension. thanks Deanohh.

 

[degenex_imp]

HAHAHA The oxygen sensor monitors exhaust gas oxygen content for the purpose of fine trimming fuel correction. The V.E. map (volumetric efficiency) also known as fuel map, has a modifier map to compensate and provide stoichiometric combustion. The oxygen sensor toggles between 0 and +1 volt. It toggles precisely and sharply at 1.0 lambda. 1.0 lambda for gasoline is 14.7afr. The ECU trims fuel while in closed loop operation exclusively at low throttle angles, input from throttle position sensor feedback. Closed loop mode is determined by a few different things. Engine temp, throttle position, and sometimes many others. Full throttle always is open loop, except for some awesome (aftermarket and high end OEM) fuel systems with a wide-band O2 sensor and specific WOT closed loop fuel control. A single wire sensor does this with one signal wire. A three wire sensor has a heater circuit to improve performance and quicken response. A four wire sensor has a heater and reference ground. These types are known as narrow band or trim type, because they only have a small range of operation. Wide band oxygen sensors are a whole different ball of wax. They are used in some oem's but not quite as much. So there you go. Don't put a eliminator on your bike. They are useful to imitate a cat converter on an exhaust system that no longer has one, and is obd2, to get rid of the check engine light for catylist inefficiency. Don't put one on your bike. Also FYI the eliminators have a timer circuit on the output to simulate cat warm up before indicating lean output. The eliminators for "performance" you get on the internet are horse crap. Don't put one on your bike.

 

[furious_blue_imp]

"HAHAHA The oxygen sensor monitors exhaust gas oxygen content for the purpose of fine trimming fuel correction. The V.E. map (volumetric efficiency) also known as fuel map, has a modifier map to compensate and provide stoichiometric .."

I get the feeling that the digital computer age has decisively cut down the shade tree for good. The only way that the lessons from the olden golden days can be relevant is if we find ourselves marooned on a desert island. Then the guys/gals that know how to make a working engine that doesn't rely a computer can get to work

 

[Waffa_imp]

"HAHAHA The oxygen sensor monitors exhaust gas oxygen content for the purpose of fine trimming fuel correction. The V.E. map (volumetric efficiency) also known as fuel map, has a modifier map to compensate and provide stoichiometric .."

I get the feeling that the digital computer age has decisively cut down the shade tree for good. The only way that the lessons from the olden golden days can be relevant is if we find ourselves marooned on a desert island. Then the guys/gals that know how to make a working engine that doesn't rely a computer can get to work

The problem is when you're stranded on an island and the only things around are high tech computer controlled stuff that never seems to work right.

 

[flynrider]

I'm stumped. Why you would want to replace the O2 sensor with a dummy in a closed loop system is beyond me.

Assuming that you haven't added something like a properly mapped Power Commander or similar independent control, I can't see the value of just dummying an input to the ECU. The only thing I see happening is possibly less efficient combustion at lower throttle settings.

It strikes me as a solution in search of a problem.

 

[degenex_imp]

Upon key up engine off, most ecu read map sensor and use that fixed value for bar pressure until the next key cycle. The enrichment adjustment is needed for a range of variables and the oxygen sensor should be left in the control loop, there just isn't a good enough reason to remove it.

 

[furious_blue_imp]

It occurred to me that 'clipping the O2' sensor might be akin to clipping the suspension adjustment wire on the new BMW's active suspension shock (it can automatically sense changes to road conditions and re-adjust the damping characteristics in about 0.1 seconds and does this *continuously*).

One could get a static rear shock setup for a particular race track, but for street riding a continually semi-active rear shock that is constantly adapting to road conditions is a real plus. It would be crazy to 'clip' that wire and throw it all away..

Thanks for the interesting discussion so far..

 

[Ack-CB11_imp]

The plug makes the ECU always run in a full rich or cold start condition. The bike will feel like it does before it gets warmed up and leans out. Fuel richness and MPG are the only changes.

 

[the Ferret]

It is very interesting, and thanks folks for keeping it civil, and trust you will continue to do so, while still trying to make your points.

For me it is fascinating how much goes into making a bike run. I am also amazed at the apparent knowledge on this board about varied technical subjects. I always thought I was fairly knowledgable about motorcycles, (shade tree might be an apt description for my knowledge) but anymore when I read discussions such as this I just sit there slack jawed.

 

[Dynaguy_imp]

I think that if you are trying to "hot rod" a CB1100, you bought the wrong bike.

 

[furious_blue_imp]

I was more amused at CBR250 guys/gals going to great lengths to get 2 more horsepower out of the 250.. (which is a big win.. nearly 10% more HP !)...

but, wanting to improve things.. It's what makes America great ! ™ yay for that !