O2 sensor simulator

[grave77]

Hi guys ... will check this out and comment?! http://www.bobblick.com/techref/proj...sim/o2sim.html

[Derek A.]

Seems kind of pointless. Why not maintain all the correct sensor levels and then adjust engine management as needed?

[grave77]

don't u think this can work fine for cars in hot areas that the O2 sensor will not work perfictly?

[Derek A.]

the o2 sensor operates in the exhaust system. How can it have a problem with heat ?

[winfred]

id guess to fool the computer if you need to remove the post cat 02 sensor on a obdII car, or remove the cat and not have a bad cat code. hey it could be used so you can use a aftermarket cat and not get a bad cat code after a year or so on a obdII car

Seems kind of pointless. Why not maintain all the correct sensor levels and then adjust engine management as needed?

[grave77]

well, when it's hot the air mass will become lower so the O2 sensor modifies the mixture to accommodate the difference, but it wasn't designed to accommodate 110F weather with high rates of humidity, even if u have a cold intake it will still be hot. I had to unplug the O2 sensor in summer time. with this simulator I can adjust the signal to get the best performance as if I put a modified O2 sensor. this is my expectations I still don't know how exactly it will affect the DME, many professional guys in Bimmer told me that I have to accept the low performance when it's summer time. but maybe such stuff can make it better.

[grave77]

Well for me I have the catalytic converter chopped off; we don’t have very strict regulations about that in our place. The idea here is to make the engine accommodate to 110 F of heat I don't know if u can imagine how u really feel the power loss in such weather!! The engine hesitates allot more than normal weather conditions. This simulator might do something to find some sort of a basic solution. I have better performance when I unplug this sensor especially at summer. Any ideas about that?

[Derek A.]

Cars do not make power in warmer weather. Its simply due to the fact that the air is less dense when its warm with high humidity. Changing the dynamic input of the o2 sensor to a static level is not going to help you out. Unless you get into a forced air induction situation there is not a whole lot elese you can do.

[grave77]

that's exactly what I said about the hot air due to hot weather, but the simulator can be setup with a knob so it wont be static too. the setting will be a try and error thing until u gain experience. or draw a scale on the knob. forcing air into the engine like turbo supercharging will do for sure and add allot of power, but I will suffer from engine overheating in the summer or I will be in need to cool up the engine oil too.

[MarkD]

Well for me I have the catalytic converter chopped off; we don’t have very strict regulations about that in our place. The idea here is to make the engine accommodate to 110 F of heat I don't know if u can imagine how u really feel the power loss in such weather!! The engine hesitates allot more than normal weather conditions. This simulator might do something to find some sort of a basic solution. I have better performance when I unplug this sensor especially at summer. Any ideas about that?

The O2 sensor simulator is used to trick the DME into thinking that you have a working post-cat O2 sensor on your car. (on OBD-II cars with cats removed). The reason it is adjustable is because the DME wants to see a certain difference in signal between the pre and post cat signals, to ensure that the catalytic convertor is actually working.

How old is your current 02 sensor? If it is old, it's output will be low (or too slow to respond) and both these cases will cause the motor to run richer than required, and you will lose power. That is why the car runs better when you disconnect the O2 sensor. (the hot air and humidity mean there is less O2 available in a specific volume of air, and disconnecting the sensor is probably leaning out the fuel slightly, especially if your sensor is bad)

The reason that motors lose power at high ambient temperatures is that the IAT (intake air temperature) sensor indicates to the DME that the timing must be retarded. There is a curve in the DME that specifies how much ignition retard to add to the base timing, dependant on the temperature.
This must be done or pinging can occur. If your car had a knock sensor (which it does not) it would be possible to operate closer to the threshold of knock.

Summary:
- Replace your O2 sensor if you have more than 30K miles on it.
(some may last longer)

- Don't waste your money and time on an O2 sensor simulator as that will not fix your low power at high temp. issue.

If you really were going to kludge this, you would want to hack into the IAT temp sensor and adjust that. But, I don't recommend thatat all.

Here is one solution that would work for you:

1) Buy a chip from me. I'll reduce the timing to compensate for your hot climate.

2) Buy and install a Safeguard knock control unit, which will detect knock and retard the timing when it is detected.
You need the one channel unit: http://www.jandssafeguard.com/index.html
Note: I am working on a prototype knock retard system using a high speed DSP which may be on the market this fall)

You need to execute both steps above, not just step 1.

MarkD