adding a resistor to the o2 input wire

[guest001]

I've seen many threads and post on adding a resistor to the IAT input wire, or whatever, or IAT mods, but that doesn't make any sense to me. Isn't the o2 sensor then end all, final adjustment to the fuel. which makes sense cause why the hell is it even there.

I can't take the entire credit for this, but it sounds like it would work. I have an older one wire o2 sensor on my car so that's what I'll be talking about. but if I were to add a resistor to that wire, which size is the question, it would lower the voltage to the ecu and it would lean out the mixture.

I actually have a wbo2 sensor, so I could throw a random resistor in there and get a good idea of how lean it is and vary the resistor accordingly.

It makes way more sense then attempting to adjust the fuel maps, because when the o2 is work its uniform and steady, or consistant as hell, way better then any attempt to lean out the fuel maps so far.

[guest001]

maybe this wouldn't work. cause the o2 sends a voltage of 0-1 to the ecu. is 0 or 1 rich cause if 1 was rich it would lower its actual output and add more fuel.

[n0rt0npr0]

right. It wouldnt' work. goto http://www.eagle-research.com/ to buy a device that will adjust your o2 sensors output

[guest001]

ok...... what the hell is that???


ok, then is the an electical device that would increase voltage?

I'm correct about the iat mod though right? cause if the computer is reading load and rpm, then getting fuel maps from the computers memory. then that duty cycle or fuel value is modified by the iat. at this point fuel is in the motor. it would take the next cycle of the engine for the o2's input to be a variable.

[kamesama980]

yes, the IAT sensor mod is just a resister and works because the IAT is a thermister... temperature varied resister.

[Hateful]

not sure which idea I like better; Lying to the o2 sensor or burning water.

[guest001]

yeah, but the question is how does the o2 actually work.

the engine would have to go throw one cycle for it to even get a reading and send the input to the ecu. so, the iat would affect the a/f ratio the first time. then on the next cycle does the ecu throw the input from the o2 into the calcualation, ONLY if your still in the same rpm/load on the fuel map. if the load/rpm changes its not going to correct it again the first time.

but I'm guess that the computer saves this info and use it next time, which would very!!!!! quickly make the iat resistor mod not do anything. and for only one trip.

the only way to do this without actually adjusting the fuel maps w/ the o2 disabled is to modify the o2 input some how. if 0 voltage from the o2 is lean and .9 is rich. you would need a device that increases voltage by .1 increments.

[kamesama980]

yes, the o2 sensor is used to adjust the whole fuel map over time, NOT for instantaneous response.

[maxxgraphix]

The O2 sensor puts out a DC voltage based on the amount of O2 in the exhaust stream. The CPU monitors this in real time at ??? cycles per second. You can watch the readings change on an advanced scan tool.

If you really want to %^&$ with your air fuel ratio, get your CPU chipped so that you can adjust the maps.

Placing ohms in the O2 circuit will just screw things up. Too lean can also result in less FE and fubard engine.

[guest001]

Originally Posted by kamesama980

yes, the o2 sensor is used to adjust the whole fuel map over time, NOT for instantaneous response.

i dunno, it seems like it does it pretty fast, cause I disconnect my battery (which resets the computer) to install eeprom chips in my computer with new tunes and when I have the o2 enabled the a/f quickly goes to 14.7 or really close to it.

maybe its just my car, cause I know there such a thing as drivability issues after resetting a ecu or disconnecting battery. not that I've really seen, but it is in repair info.