After hearing about a product which fit onto the air charge temperature sender of the 300 that basically used a resistor to tell the computer that it was colder outside than it actually was, to in theory gain power through a larger fuel shot. The problem is that the gain would be offset by the O2 sensor detecting a rich condition, and leaning the mixure out.
A good idea thwarted again by the retardedly intelligent Ford computer.
This gave me the idea, however, why couldn't one insert a resistor into one of the O2 sensor wires, thereby telling the computer the engine is running leaner than it actually is, and the computer compensating by delivering a bigger fuel shot, thereby giving more power?
Now, assuming that this works, I would want to try varying sizes of resistors in order to find the one that best suits my needs. What range of resistors might I want to look into for this purpose, and which wire coming out of the O2 sensor would I want to put it in?
Also, assuming that it won't work, somebody thouroughly crush my idea so I won't try it anyway and mess something up.

 

still a bad idea, those are voodoo and actually reduce engine life by adding more fuel than needed. the fuel washes down the cylinder walls of the oil and gets into the crank case. then it gets pumped into the oil system and destroyes the bearings.

crushed enough for ya? :-)

 

Ok, is this the same as a "simulator", right? I got two oxygen sensors, one upstream and one downstream with one cat. I guess the second one montors the gas air ratio? The computer has already compensated the ratio with the help of the first one. Whatever the voltage output on a properly functioning engine of the second sensor should be considered in getting the same resistance in one that can function properly without a cat. I've pondered the idea that once your engine starts burning oil, your cats don't last very long and that this may also alter the air fuel ratio determined by oxygen sensor resistance, and then might mess up a properly functioning engine, it already has enough trouble. With a clogged cat, wouldn't back pressure eventually start to burn the valve?Taking the cat off putting a proper resistor in there (id like to try that), oh yeah and put some better oil in there. This oil will clog cats. I believe that the computer receives information from the sensors hundreds of times a second, and that the resistance changes from each sensor between sending this back, so thats the only way the computer can monitor changes and compensate the air fuel ratio. So mabey a resistor that is connected to the first one, using a (-) value of o from the first one but will follow its voltage output but only at a negative value subtracted from a catalytic converter. This way, the computer is really fooled and delivers the proper fuel shot. This way, the resistor is not "dead" everythings cool, the computers fooled, and nothings lean, know what i mean?

 

An O2 sensor is not a variable resistor like the IAT sensor. An O2 sensor generate a voltage that is processed by the PCM. Therefore, adding a resistor will not work.

 

Just have to say. Is there any possible way that you can achieve this.?I don't know much about resistors and what not but whatever the heck its called theres has to be some easy logic for the human brain to fool a gas sniffin computer to figure out how to burn right.

 

There is indeed. Don't listen to the previous poster :P The trick is to use both a resistor and a capacitor. Both can be acquired extremely cheaply.

Check the PM i sent u

 

Thanks for the info, once the cat goes, just had it replaced, i'm not spending another back breaking paycheck or so on another one. I have better interests in saving my money that will help my truck burn better and cleaner. Not too mention wheels, body panels, egr valve, vaccum hoses, thermostat, and many other things. i catalytic converter isn't going to help get hopefully another 100000km on it, and with my limited bugdet, it is the least of my worries. And and this point in time, it definetly won't save the planet, if you know what i mean.

 

I re-read your questions. I am not an expert, thought i did stay at a holiday in last night

for us OBD-2 peeps, simulating that downstream o2 sensor (after cat) is perfectly fine.

for ya'll to completely replace the upstream o2 sensor(s), that's not a good idea i do not believe. but you two don't have the intention of doing so however

i really think you can do what you (at the least the first poster) wants to do. you will either want to step up or down the voltage sent back to the ECM by a certain margin. you will need to know a bit about electrical theory to figure out how to do so

 

does the PCM process purely the voltage, or total current? if just voltage, you should be able to insert a resistor into the circuit and lower it. if total current, then yes a resistor wouldn't make a difference i don't think. (ohms law)

an o2 sensor isn't a variable resistor, but it acts like one

 

The signal from the O2 sensor feeds into a high input impedance comparator.
When the PCM goes into a closed loop mode, it is constantly varying the fuel mixture, while monitoring the voltage level from the O2 sensors. Only one thing acts like a variable resistor, that's a variable resistor!!! A lot of work
has gone into making this an efficient system, why mess it up????

Since you don't seem familiar with how an O2 sensor operates, this URL
is easy to understand:

http://hostingprod.com/@aa1car.com/library/o2sensor.htm

 

The O2 sensor only knows two things: zero volts and one volt. Adding a resistor won't do anything for you. The current output of the sensor is so low the resistor would probably always read zero.

The resistor in the IAT sensor also causes the computer to reference a more aggressive spark map. This is where gains come from with this mod on some vehicles.

 

I disagree! An O2 sensor is analog, not digital, and the signal voltage will vary with fuel/air mixture. Look at the waveforms in the URL I posted.

 

The waveforms are of the average sensor reading the scope sees, but I was unclear in my first post. The O2 sensor only knows the difference between rich and lean of 14.7, not necessarily 0 and 1 volt. Only a wide band O2 sensor can quantitatively measure the airfuel ratio. A regular O2 sensor can only measure it qualitatively. Regardless of what the O2 sensor tells the computer, the computer's interpretation of the data is digital. Regardless, the resistor isn't going to do anything productive to the signal.

 

Wrong again, scope pictures show the dynamic signal amplitudes, if you measure the O2 output with a voltmeter, that would be an "average" value.
The signal from the O2 sensor is treated as a analog signal by the PCM. The
O2 signal is then digitized with a A to D.

 

I will definately read up :P

(because i still can't see why a resistor can't limit/step down the voltage being sent to the PCM to trick the PCM to think it's reading richer - i suppose this is an opportunity to learn more about theory)