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o2 sensor reading erratic

 
Old 11-04-2015, 07:43 PM
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Default o2 sensor reading erratic

Hey guys,

I have a new o2 sensor from KO I had shipped to the shop and had the dyno shop install it while they had my car, the reading is coming through as erratic after picking the car up from the tuners. The reading fluctuates between as low as 8:1 and as high as 20:1 at idle, has anyone heard of a wideband failing within a week of install and dyno tuning?
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Old 11-04-2015, 07:54 PM
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Where is the sensor located in the system? I know Innovate's sometime overheat and damage the sensor if it's too close to the exhaust valves.

Who is KO? What wideband? How is it wired?
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Old 11-04-2015, 08:46 PM
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KO Racing - sensor is located roughly where the shifter turret is in the system.
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Old 11-04-2015, 11:31 PM
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I pulled the sensor and started re-calibrating it. During re-install I noticed the harness coming off the ecu had a wear patch in the loom and two wires were worn through the sheaths.... Last time I pay someone to do even a simple thing on my car unsupervised. I'm going back out now to cut and patch it, then re-re-recalibrate the sensor.
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Old 11-05-2015, 12:32 AM
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Originally Posted by Der_Idiot View Post
Hey guys,

I have a new o2 sensor from KO I had shipped to the shop and had the dyno shop install it while they had my car, the reading is coming through as erratic after picking the car up from the tuners. The reading fluctuates between as low as 8:1 and as high as 20:1 at idle, has anyone heard of a wideband failing within a week of install and dyno tuning?
hello again der

Originally Posted by Der_Idiot View Post
I pulled the sensor and started re-calibrating it. During re-install I noticed the harness coming off the ecu had a wear patch in the loom and two wires were worn through the sheaths.... Last time I pay someone to do even a simple thing on my car unsupervised. I'm going back out now to cut and patch it, then re-re-recalibrate the sensor.

yuah that

also some sensors read like **** at low airflow. wideband sensors that is
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Old 11-05-2015, 12:33 AM
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solution is tune by sound and smell

surely you can do that with your idle. if not then you shouldnt tune
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Old 11-05-2015, 04:39 AM
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Cut, soldered and shrink wrapped the harness, put things back together and calibrated the sensor. Things run much smoother now, though the tune has -2.5* at 16psi so torque is lower than previously. Seems there's a tear in my (new) inner shifter boot.

No luck lately with this thing, I swear.
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Old 12-02-2015, 06:10 PM
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In Hydra 2.7 if the system voltage runs too high I've seen the WBO2 reading go erratic. In these cases I turn the voltage target down till the datalogged WB trace cleans up. Mostly a NB problem with the ECU regulated voltage, can't do this with 90-97 alternators.

Are you saying that they set your timing to 2.5° ATDC at 16 PSI????? Are you running 85 octane??? Not ideal. I *prefer* to keep my advance at torque peak 10° advanced or higher at my max boost level so the EGTs don't go crazy, can use this to limit my boost for any given octane when doing a conservative tune. There are always lots of considerations but this is one of them.
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Old 12-05-2015, 04:19 AM
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Sorry, that didn't quite make sense. They had -2.5* compared to my previous map at that particular point. On the tune they have knock amp turned on and knock volts at .012, I was seeing some events in the log close to or at this level so I backed the timing off to their map. Torque felt great, but if it's actually pinging up there... I'm forgetting how 2.7 handles the knock sensor, I swear something was changed.

I still have an insanely annoying intermittent issue around 2250-2750 where the car bucks progressively more extremely until I either push into boost or let off the throttle completely. Log doesn't show anything that would indicate erratic sensor readings or anything like that. Maybe has something to do with the CAS+crank sensor 36+2 conversion..?

I've been meaning to do more work on the car, but it got cold quick up here and we have to move so the car's been parked for a while. Called the shop and complained about the shift boot and wiring and never got a call back, so they're being written off. I'll but a new rubber boot and call it good.
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Old 12-05-2015, 01:49 PM
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Originally Posted by Der_Idiot View Post
Sorry, that didn't quite make sense. They had -2.5* compared to my previous map at that particular point. On the tune they have knock amp turned on and knock volts at .012, I was seeing some events in the log close to or at this level so I backed the timing off to their map. Torque felt great, but if it's actually pinging up there... I'm forgetting how 2.7 handles the knock sensor, I swear something was changed.

I still have an insanely annoying intermittent issue around 2250-2750 where the car bucks progressively more extremely until I either push into boost or let off the throttle completely. Log doesn't show anything that would indicate erratic sensor readings or anything like that. Maybe has something to do with the CAS+crank sensor 36+2 conversion..?

I've been meaning to do more work on the car, but it got cold quick up here and we have to move so the car's been parked for a while. Called the shop and complained about the shift boot and wiring and never got a call back, so they're being written off. I'll but a new rubber boot and call it good.
Post a log.

And if you look at the plugs with a 10x magnification glass and good lighting, you can "see" if there is any detonation by looking at the porcelein. This is actually how I setup my knock sensor to detect knock, and the plugs don't lie, but they suck for RT knock detection of course.
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Old 12-07-2015, 04:18 PM
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Bucking could be a number of things but I would start with a datalog showing AFR, advance, MAP and throttle position. Could be a dodgy TPS zero calibration or a floating TPS signal, or it could just be going lean.
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