a few days ago i noticed a change in my a/f r it richened up from 14.7-1 to about 13.9- 1

with no adjustments



this is measured on an lm1 wideband. i recalibrated my meter and i still am getting the same reading.



what could be the cause of this change? is it a software/hardware problem or do you think it could be in my air temp map? it has gotten hotter out lately but wouldn't the air temp map reduce fuel when its hotter?



has anyone else encountered this.

thanks for your input.



my coolant temp sensor seems to be reading fine.

 

yeah it could be a temp correction map. air temp, barometric....

 

is there any way to tell exactly what caused this change

 

saw a thread somewhere else, it could be the fuel too. in CA we havent had mtbe for a while, but i guess not everyone switched over until recently

 

This might be completly unrelated, but here in MN when they switched over to the summer grade fuel, I noticed a +7-8mpg change on my 95 volkswagen.