Same car that I helped to do cam/head swap with LT's has recorded two DTC codes #63 and #13- left and right O2 sensor failure. Yesterdat the car was smoking white a lot and had an SES light due to O2 sensor failure, but today it smokes much less, and in drive the car doesn't smoke at all. In closed loop the car doesn't smoke at all, and this confuses me. Datamaster's recorded O2 mV values today were in 400-450 range in a 20 minute trip, which doesn't look bad at all. Is there anyway possible the O2's started working fine again, or once the O2's fail and you get the code, they have to be replaced. My friend is totally broke and doesn't have $130 to dump to new O2 sensors. Should I leave his car in closed loop with a bit of white smoke, or program the ECM to always be in open loop? LT headers and O2 sensors don't go good together

 

I'm not sure if this is of any relevance, but my O2 mV range from low 100's to 900's when it's in closed loop mode. They start out at 450 when I first crank my car, and slowly work there way up to the mid-900's before they start to "swing" and go into closed loop.

 

13 and 63 are for the heater circuit on the O2s. Check fuses if the codes are not old, stored codes that have not been cleared. If your O2s are staying at 400-450, they are not working.

 

Oh ****...um thats what both of mine are at Glad I checked this. *Adds another item to list of stuff to fix on LT1 Maybe its cause mine wont enter closed loop..

-Dustin-

 

Thanks shoebox, I will check the O2 sensors tomorrow. I thought that 450 is the value when O2's not working? The O2 values did jump a couple times above 500, but the car was never reved above 2500 rpm in the test drive, and there was no fast acceleration.If my O2 sensors were working, what should I see on datamaster?

 

400, 450, it just depends on what voltage comes back to the PCM. It might not be identical on all cars.
In closed loop, the reading should be rapidly jumping all over the place [100-900mv](except that they will stay pretty steady at WOT). You can read up on scanner data stuff on Injuneer's website.

 

ran datamaster on friends car today after clearing the code, and the O2 readings today were in 100-600 range for one O2 and 300-500 for another, which doesn't look right. I guess BOSCH heated O2 sensors are crap, gave Cramer a call today At least car doesn't smoke at all anymore