o2 cross counts

[Haynesie]

on the scanmaster is this number represented by CC, and also what would high numbers mean, and would this affect fuel mileage, what about it very low, i read on gnttype that it should be around 10-20, any info would be appreciated

 

[Shane]

I'm not exactly sure what it does myself, but I've been told that it just means the 02 sensor is working. It should cycle up to 255 and then go back to 0. It's a counter.

 

[Robbie-87plz]

I'm pretty sure it's the number of times the ecm/O2 sensor has crossed the "stoich" threshold... It'll go up like stated before and reset, should it move very slowly, I believe your O2 is on the way out, replace... someone correct me if I'm wrong.

 

[iamjeff]

I'm pretty sure it's the number of times the ecm/O2 sensor has crossed the "stoich" threshold... It'll go up like stated before and reset, should it move very slowly, I believe your O2 is on the way out, replace... someone correct me if I'm wrong.

that is my understanding

-jeff

 

[Blazer406]

Sometime mine goes from 0-255 in 6 or 7 seconds..... sometimes it takes 30 seconds..... if I am at WOT.... it doesn't move. That is the way it is supposed to do. If while idling or cruising (closed loop only).... your cross counts aren't counting pretty quick..... you probably have something not working correctly...... Check your BLM'S too ... to see if the ecm is trimming or adding long-term fuel.....

 

[2QUIK6]

A healthy O2 sensor should cycle the cross-counts from 0-255 in less than 90 seconds at idle with engine at oper temp. If it takes more than 90 seconds to cycle thru, the O@ is getting weak and its time to replace it.
At cruise it can cycle thru very quickly cause the exhaust gases are hotter....the time should be measured at idle.

 

[86BGN]

A healthy O2 sensor should cycle the cross-counts from 0-255 in less than 90 seconds at idle with engine at oper temp. If it takes more than 90 seconds to cycle thru, the O@ is getting weak and its time to replace it.
At cruise it can cycle thru very quickly cause the exhaust gases are hotter....the time should be measured at idle.

What about an open loop idle chip? Wouldnt the cc's stay unchanged until you go out of open loop to closed loop.

 

[2QUIK6]

What about an open loop idle chip? Wouldnt the cc's stay unchanged until you go out of open loop to closed loop.

Not sure, I only have 1 chip that stays in open loop at idle and I haven't noticed if the O2s are still active even when in open loop...for some reason I'm thinking they are, its just when in open loop, the O2 sensor measurements are not used by the ECM to control fueling.

 

[Blazer406]

What about an open loop idle chip? Wouldnt the cc's stay unchanged until you go out of open loop to closed loop.

Not really... at least not in my case. (stock ECM .... stock chip) My car when first cranked from cold..... idling in open loop..... O2 cross counts count fairly rapidly..... I guess the mixture in the ECM is pretty close to stoic. You would have to be significantly away from stoic. (and stay there) for the cross counts to not go up. I suspect the open loop idle chips.... in an effort for great idle quality.....probably err to the rich side... on the programming.... which wouldn't allow for cross counts to increase....... however.... in the case of the turbotweak chip (per their website)....does still have long term fuel trim (BLM) still enabled...... so the computer still can learn........

HTH