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Discussion Starter · #1 ·
I'm getting ready to start my car for the first time on the ECUMaster EMU. I'm wondering if this is a bad idea when I don't have a wideband O2 sensor, I only have the stock O2 sensor at the moment.

I do however have working IAT, CLT, MAP, TPS, etc.
 

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Wideband only comes in use when tuning at higher RPM under load. Fine to get your base tune sorted especially at idle. Get it running well first before turning up boost.
 

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Discussion Starter · #3 ·
How can I determine if the O2 sensor is actually working, as in, how can I determine if the ECU is receiving the signal correctly?
 

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You use a scanner with scope feature to monitor o2 sensor reading to n from ECU, EMU has port to plug in a scanner or laptop for monitoring PIDs sensor/actuators readings
 

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Discussion Starter · #5 ·
You use a scanner with scope feature to monitor o2 sensor reading to n from ECU, EMU has port to plug in a scanner or laptop for monitoring PIDs sensor/actuators readings
I know I can look at the actual output of any attached pin for the EMU using a laptop, I'm curious what to look for.

In particular, I want to know if the sensor works before even attempting to start the car. I don't want to flood the engine or have something else bad happen.

How can I tell from the EMU scope output of an idle O2 sensor that it is working? What values would indicate a good signal? What values would not?
 

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...How can I tell from the EMU scope output of an idle O2 sensor that it is working?
You can't. Until it is completely warmed up, an O2 sensor is just a chunk of ceramic, and it will produce no signal whatsoever. Once it is warmed up, it will put out a voltage if you give it a rich mixture. The way that you tell that it is working is by watching the voltage go up and down in closed loop as the mixture oscillates between rich and lean.
 

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Here's what I would try. Pull the sensor out of the bung, turn on ignition, and cycle the sensor in an out of a propane torch flame while monitoring the scope. In normal operation the signal voltage cycles between 0.1 and 0.9 volts approximately. This test may or may not work. Give it a shot.

PS> Regarding your concern about something bad happening following startup. O2 sensor feedback is ignored by the ECU from startup until it enters closed loop. There is plenty of bad stuff that can happen in that interval, which can be a minute or longer. But open loop settings of the ECU should make the engine run reasonably well if not perfect during this time. If you're concerned about fueling you really should have a wideband AFR sensor that lets you monitor AFR accurately. Note even these have a warmup period which can be 30 seconds. You can pre-warm the wideband sensor by turning on ignition and allowing the sensor to go through warmup, but this carries some risk for the longevity of the sensor.

PPS> I missed the point of your post entirely. Does you ECUmaster even have closed loop control? Many of these gizmos don't. In this case it wouldn't even matter what the O2 sensor feedback is. This is why you should never operate the thing without a wideband.
 

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Correct as both previous posts stated, the o2 sensor only starts to produce a reading once engine is up to temp.
Look for a switching voltage between 0.1-1.0v on a normal good operating sensor, remember o2 sensor is a piezoelectric type sensor which produces its own voltage signal n feedbacks to ECU based on oxygen, a/f ratio
 
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