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Discussion Starter #1
A few weeks ago I took my 2006 Elise with a BOE Rev 300 supercharger to get smogged here in Colorado. The car passed last time I did this, two years ago. This time however the Oxygen Sensor Heater displayed as "Not Ready". I have since been driving the car around town and on the highway trying to get the Oxygen Sensor Heater to cycle so that it displays "Ready". I scanned for codes and in addition to the Oxygen Sensor Heater displaying Not Ready, a P0113 code popped up for "Intake Air Temperature Circuit High Input". I imagine they are not related but figured I would include that in this thread.

Anyone else have this issue where it took this long to get the Oxygen Sensor Heater to cycle? Any recommendations?
 

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shay2nak
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Do a cold start, let the car idle for 10 min. Drive around without WOT and hard braking. Easy gas and brake. Don't go faster than 60/65mph on FWY. Does the CAT set?
 

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I've been doing the 10 min idle but not going easy on gas and brake or keeping it under 60 MPH. I'll try this tonight.
 

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Discussion Starter #4
Did the ten minute warm up tonight then drove around for half an hour not going above 60MPH. Mix of street and highway. Still no luck in getting the sensor heater to cycle.
 

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https://www.nyvip.org/PublicSite/OBDII/oxygen-sensor-heater-monitor.html
>>>>
OBD II Readiness Monitors

Non-Continuous Monitors

Oxygen Sensor Heater Monitor

OBD II equipped vehicles use heated oxygen sensors. Heated oxygen sensors have an internal heater circuit that brings the sensor up to operating temperature more quickly than an unheated sensor. The heater will bring the sensor up to operating temperature within 20 to 60 seconds depending on the sensor, and also keep the oxygen sensor hot even when the engine is idling for a long period of time. The faster the oxygen sensor heats up, the quicker the PCM can enter closed loop fuel control, optimizing catalytic converter efficiency.

On most OBD II systems the oxygen sensor heater monitor runs concurrently with the oxygen sensor monitor or continuously when the engine is running. However, the successful completion of the monitors are independent events. Typically the PCM will enable the monitor, conditions for completing the oxygen sensor monitor will be met and that monitor will successfully complete. Some enabling criteria to complete the oxygen sensor heater monitor may not always occur and the heater monitor goes uncompleted for several drive cycles. This may happen more frequently as the sensors age and the sensors’ heating element deteriorates.

During oxygen sensor heater monitoring the PCM turns the heater strip circuit on and off for each sensor and looks for an expected change in current. On some OBD II systems the PCM continuously monitors current flow through the heater circuit. The heater circuit of each oxygen sensor is evaluated independently.
<<<<<

what this tells me is the heater may be weak in your O2 sensor. If the wiring were defective or if it were dead I think you would throw a code, but since it gets hot enough to go closed loop maybe there is no code.

just guessing
 

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2007 Lotus Exige S
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Did they read the OBD2 the last time you had emissions done in Colorado? If so, did that have the same tune?
 

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Heater is usually an instant test (just a resistance check under load), so it's probably a bad O2 sensor unless it's disconnected.

This should throw a code for the heater circuit though. It'd be worth checking with BOE to see if they disable this in the tune, in which case they can probably flip the readiness status for you.
 

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shay2nak
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Took me 30 miles to set.

What o2 voltages are you seeing when you select Live Data on the reader?
 

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Took me 30 miles to set.

What o2 voltages are you seeing when you select Live Data on the reader?
O2 voltage is different than the heater circuit. Two circuits on the O2 sensor. The actual sensor reading can give you completely normal voltages even with the heater being completely faulty.
 

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Yes, two years ago, with the same tune, the OBD2 was read and passed emissions. I'm leaning more and more on a sensor going bad.
At least you can rule out the tune then. Not the first I've heard there is some magic to make sure everything is set to ready but I'd likely be replacing the sensor.
 

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Discussion Starter #13
Yes, two years ago, with the same tune, the OBD2 was read and passed emissions. I'm leaning more and more on a sensor going bad.
At least you can rule out the tune then. Not the first I've heard there is some magic to make sure everything is set to ready but I'd likely be replacing the sensor.
I'll be replacing sensors this week and will report back on the results. Feeling pretty good that this is the right path.

Are you doing the Emich sponsored track day at the end of April? I'll be there for the afternoon session.
 

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I'll be replacing sensors this week and will report back on the results. Feeling pretty good that this is the right path.

Are you doing the Emich sponsored track day at the end of April? I'll be there for the afternoon session.
I am planning on the Emich day and I think CECA is there the following weekend too.
 

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shay2nak
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UPDATE - the IAT sensor was failing and the O2 sensor had a failing heater. I'll be swapping both. I think my issues are resolved. Thank you everyone for your help!
Cool! How did you determine they both were bad?
 

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Discussion Starter #17
Cool! How did you determine they both were bad?
The IAT would fail once it warmed up; it dropped out to -40F when warm, then after cooling down it would read properly. I was going into limp mode after my last few track events too. Not right away, but after a session or two, which also seems to coincide with the IAT sensor. The wires to the ECU looked good so I figured I didn't need a new harness.

For the O2 sensor, the downstream sensor that monitors the catalyst was showing a failing heater, where I was getting very low resistance compared to the upstream unit. I'm replacing both O2 sensors while I'm in there though.
 

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Discussion Starter #18
UPDATE - well, the car still won't pass emissions as I can't get the O2 sensor heater to display as ready. I talked with BOE who said their tune doesn't support this sensor (wish they would have told me this a few months ago but I digress). They said I would need a different tune. I asked how to go about getting this different tune and then.....radio silence from them. A bit annoyed at their customer support or lack thereof at the moment.

So, anyone have any idea how I get this other tune on my ECU? I have the fastworks cable but not the software.
 

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shay2nak
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UPDATE - well, the car still won't pass emissions as I can't get the O2 sensor heater to display as ready. I talked with BOE who said their tune doesn't support this sensor (wish they would have told me this a few months ago but I digress). They said I would need a different tune. I asked how to go about getting this different tune and then.....radio silence from them. A bit annoyed at their customer support or lack thereof at the moment.

So, anyone have any idea how I get this other tune on my ECU? I have the fastworks cable but not the software.
I haven’t been thrilled either.

My best advice is to find a stock ECU to buy and swap it out. That’s what I do.
 

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UPDATE - well, the car still won't pass emissions as I can't get the O2 sensor heater to display as ready. I talked with BOE who said their tune doesn't support this sensor (wish they would have told me this a few months ago but I digress). They said I would need a different tune. I asked how to go about getting this different tune and then.....radio silence from them. A bit annoyed at their customer support or lack thereof at the moment.

So, anyone have any idea how I get this other tune on my ECU? I have the fastworks cable but not the software.

Color me surprised.
 
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