weird O2 sensor readings... WTH?
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
weird O2 sensor readings... WTH?
i posted this over in scan and tune but nobodyt seems to go over there...
I checked my O2 readings with autotap and one of the simulators is a steady 425... the other sim will hold 435 and then suddenly jump to 850 or so for a minute and then bounce back to 435.
the O2 sensors read around 20-70 at idle and then when i start accellerating they start jumping around but still not in the normal sine wave like they are supposed to. they go like 200-300-400 but every few seconds they might jump up over 600 like once.
i bought 2 new O2 sensors but i am hesitant to replace the old ones until i am more certain that they are bad (cuz the new ones are $51 per sensor).
any ideas? i should tell you that this is a new engine (600 miles) with a new ed wright program, and that all engine info is in my sig if you need to look for more info.
TIA! :confused:
I checked my O2 readings with autotap and one of the simulators is a steady 425... the other sim will hold 435 and then suddenly jump to 850 or so for a minute and then bounce back to 435.
the O2 sensors read around 20-70 at idle and then when i start accellerating they start jumping around but still not in the normal sine wave like they are supposed to. they go like 200-300-400 but every few seconds they might jump up over 600 like once.
i bought 2 new O2 sensors but i am hesitant to replace the old ones until i am more certain that they are bad (cuz the new ones are $51 per sensor).
any ideas? i should tell you that this is a new engine (600 miles) with a new ed wright program, and that all engine info is in my sig if you need to look for more info.
TIA! :confused:
Instructor
Joined: May 2003
Posts: 183
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From: San Jose CA
Re: weird O2 sensor readings... WTH? (SonnyinVA)
O2 sensor readings are all over the map exceopt at WOT. Its nornal to see from 300 to 950 readings in closed loop with multiple crossings. At WOT you should see 875 to 900 readings gradually increasing with rpm if your tuned to max lean torque. Most stock chips will run rich so you will 900 to 950 readings.
Advanced
Joined: Sep 2000
Posts: 75
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Re: weird O2 sensor readings... WTH? (SonnyinVA)
Does AutoTap tell you if it's in open or closed loop? Maybe it's staying in open loop and not providing the correction.
I'm don't know if AutoTap tells you that or not.
Just a thought.
Gordon
I'm don't know if AutoTap tells you that or not.
Just a thought.
Gordon
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: weird O2 sensor readings... WTH? (SonnyinVA)
Since you are seeing no zero-crossing at idle I think you may need heated O2 sensors due to the LT headers.
If the O2 sensors are now further from the exhaust ports than with the stock setup or the LT headers are not ceramic coated in/out this is a sure bet.
If the O2 sensors are now further from the exhaust ports than with the stock setup or the LT headers are not ceramic coated in/out this is a sure bet.
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
Re: weird O2 sensor readings... WTH? (65Z01)
i'm pretty sure the stock sensors on a 96 are heated sensors. they have 4 wires...
the weird part is that at idle they are not crossing over 450. they just stay pretty much below 100. it is only when i start to accellerate or rev it up that they go up to a fairly steady 800-something. and both of them are the same way. i wouldn't think they would both go bad at the same time.
who knows... :confused:
the weird part is that at idle they are not crossing over 450. they just stay pretty much below 100. it is only when i start to accellerate or rev it up that they go up to a fairly steady 800-something. and both of them are the same way. i wouldn't think they would both go bad at the same time.
who knows... :confused:
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Re: weird O2 sensor readings... WTH? (SonnyinVA)
Tie into the wire right near the sensor itself. If you then get readings, your wire is shorted/open. It its still dead or steady, then you either have a bad sensor, or need a heated O2.
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
Re: weird O2 sensor readings... WTH? (ski_dwn_it)
hey jesse,
i am getting readings already, they are just strange ones (at least i think so). neither one is "dead". and i'm pretty sure the 96's come stock with heated O2's.
maybe i wasn't clear... at idle the reading fluctuates but it is within the range of 20-80. when i start to accellerate it goes to a range of about 800-900 and fluctuates within that range.
i am getting readings already, they are just strange ones (at least i think so). neither one is "dead". and i'm pretty sure the 96's come stock with heated O2's.
maybe i wasn't clear... at idle the reading fluctuates but it is within the range of 20-80. when i start to accellerate it goes to a range of about 800-900 and fluctuates within that range.
