HI mcD
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I have recently installed headers. I have closed loop on my sled for over 2 years (zero problems).
I got the header tune from TD and reflashed. The sled shows normal AFR ranges for a second. Then when you apply gas and come back off of it it goes crazy. I get AFR on the gap flasher in the 20s and on the dash it will whatever the gap flasher is 2x! So like 20 AFR on the gap flasher and 40 AFR on the guage/dash.
Anyone got any ideas? o2 sensor fubar? Something else??
I got the header tune from TD and reflashed. The sled shows normal AFR ranges for a second. Then when you apply gas and come back off of it it goes crazy. I get AFR on the gap flasher in the 20s and on the dash it will whatever the gap flasher is 2x! So like 20 AFR on the gap flasher and 40 AFR on the guage/dash.
Anyone got any ideas? o2 sensor fubar? Something else??
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I would definitely swap out the O2 sensor as the first step in trouble shooting the issue as thats what my guess is the problem.
You should also check your header install and ensure that the connections are secure.
Years ago I had an Apex with a cracked exhaust just ahead of the O2 sensor that gave extreme AFR readings like you are getting.
You should also check your header install and ensure that the connections are secure.
Years ago I had an Apex with a cracked exhaust just ahead of the O2 sensor that gave extreme AFR readings like you are getting.

KnappAttack
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I had a module go bad once. I think it got wet enough where I had it mounted just behind the chaincase before. Bought a new module from Amazon or EBay I forget, but they are cheap out there, cut the plug in off the old one and crimped it onto the new module, mounted it up front so it wouldn't get wet again and has been good since. New module came with a new 02 sense as well but the sensor wasn't my issue.
I pickup a spare module from amazon to keep in parts heaven as well.I had a module go bad once. I think it got wet enough where I had it mounted just behind the chaincase before. Bought a new module from Amazon or EBay I forget, but they are cheap out there, cut the plug in off the old one and crimped it onto the new module, mounted it up front so it wouldn't get wet again and has been good since. New module came with a new 02 sense as well but the sensor wasn't my issue.
REDLINE 1
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Interesting, does it matter if it’s a different brand or notI had a module go bad once. I think it got wet enough where I had it mounted just behind the chaincase before. Bought a new module from Amazon or EBay I forget, but they are cheap out there, cut the plug in off the old one and crimped it onto the new module, mounted it up front so it wouldn't get wet again and has been good since. New module came with a new 02 sense as well but the sensor wasn't my issue.

KnappAttack
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Interesting, does it matter if it’s a different brand or not
Don't know, I've only used the AEM modules. https://www.amazon.com/AEM-30-0310-...mzn1.fos.9fe8cbfa-bf43-43d1-a707-3f4e65a4b666
Last edited:
REDLINE 1
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Mines an ECU master
AAdavis
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So these hi #s are on closed throttle? How do you get the readings on the dash? What model Winder do you have?

KnappAttack
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Mines an ECU master
Probably why you are having problems. I've heard that brand was more prone to failure.
The OP is a SW with "closed loop" fuel management available from Turbo Dynamics and HurricaneSo these hi #s are on closed throttle? How do you get the readings on the dash? What model Winder do you have?
For closed loop you need an aftermarket O2 sensor, module, and 'Dash Flash"
A stock SW can not display O2 readings.
If you shut the sled off and restart does the AFR return to normal?I have recently installed headers. I have closed loop on my sled for over 2 years (zero problems).
I got the header tune from TD and reflashed. The sled shows normal AFR ranges for a second. Then when you apply gas and come back off of it it goes crazy. I get AFR on the gap flasher in the 20s and on the dash it will whatever the gap flasher is 2x! So like 20 AFR on the gap flasher and 40 AFR on the guage/dash.
Anyone got any ideas? o2 sensor fubar? Something else??
Does the AFR read normal if you haven't gone full throttle and only read high after going full throttle for a long period?
Does the AFR only act up when the lower tunes are selected?
If you have a multi tune bundle try going full throttle on the highest horsepower setting and see if it happens.
REDLINE 1
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No problems with mine. I was just curious about buying replacementsProbably why you are having problems. I've heard that brand was more prone to failure.
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