emulated wideband to stock ecu

[MmmBoost]

ive got my innovate lc-1 hooked up to send as emulated signal to the stock ecu to keep it happy. its working fine. the only thing i havent done is get rid of the check engine lite (code 21) for no sensed resistance on the heater wires. tsrm says spec is 3.0 to 3.6 ohms.

if i take a 1/2 watt 3.3 ohm resistor and use it across those wires, will anything burn up? im not sure 100%, but by my calculations (ohm's law) it would be around 4-5 amps with 14.5 volts and 3.3 ohms resistance. is that how much current the stock o2 sensor's heater pulls?

edit: holy hell, i pushed an extra button. the amperage would be 4 to 5 amps... lol

 

[jetjock]

if i take a 1/2 watt 3.3 ohm resistor and use it across those wires, will anything burn up?

Yeah, the 1/2 watt resistor will. I recently helped a member out with this. Maybe he'll respond. Btw, your math is a little off...

 

[supraguy@aol]

will a wideband O2 sensor last a good long life like the stocker?

 

[jdub]

Depends on it's location...near the flame front (in the stock bung), will reduce it's life.

 

[MmmBoost]

whoops, miscalculation...

jetjock, you wouldnt happen to remember who that was would you?

also, if that resistor would cause a problem, is there another way out besides using the stock sensor?

 

[jetjock]

Yeah, I would, but I'll help you out.

First, current flow through a sensor falls as the sensor warms up. In the original stock sensor it settles to around 1.5 amps @14.5 volts. The behavior is normal for any resistance based heater. If you have a modern replacement sensor with a smaller heater, one designed for a different vehicle, or a universal (all of which "work" but none of which are recommended for technical reasons I won't go into) it'll likely be less.

Second, even if your math was right you're not calculating for power. Try here:

http://tinyurl.com/j6ocf

Then try here:

http://tinyurl.com/yqxyho

You might be able to get away with a 25 watt wirewound package if you can find one close to the same resistance. They're on that site too. Bottom line is you only need 1-2 amps to keep the ECU happy.

 

[mkIIIman089]

Oops, missed this earlier.

25 watt wirewound @ 4 ohms will work, I recommend the second link jet posted though as a probably better alternative.

 

[MmmBoost]

so im making the conclusion that the ecu only needs to see some resistance... the actual amount isnt very important, it just cant be and open or closed circuit....

thanks very much you guys! hopefully ill get it figured out. also, on a side note, i thought that my car was running very sluggish due to being in limp mode due to the o2 code, however i found today that my cam timing is 1 tooth off on each cam. guess i shouldnt have rushed so much putting it all back together

thanks again for that link, that seems to be just what i was looking for! i did also find on the innovate wideband forums that some users are using an 18 watt brake light bulb to simulate the resistance, however i like the resistor in the second link better. wonder if i can find one in town...

 

[mkIIIman089]

Pay close attention to the technical documentation, or no matter what you get you'll burn it up.

I ran with no sensor hooked up (narrowband simulated, like you) for a while and I noticed no change at all in performance or fuel economy.

 

[Halsupramk3]

also be careful what the resistors pulls. i tried to similate this heater with some radio shack resistors and must not have guessed correctly. about a year later the heater drivers or whatever they are called burned up in the ecu so the code 21 never went away even with a good oem O2 sensor till i replaced the ecu.