O2 Sensor Eliminator

[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 !