Hi guys, I am having a issue with my O2 readings at WOT all of a sudden on an 86 T. I have had 3 O2s in it now and they are all reading the indetical same thing. 2 of these were Caspers heated and now a stock one. The car just started doing this on the way to the track the other day, until then the car was like clock work.
It reads fine all the way until you hit wide open throttle then all of a sudden the O2 readings go to the basement with readings going from .790/.820 under 1/2 to 3/4 throttle to .03-.06 under wide open throttle. But still pulls fine and hard and has no knock. I have pulled enough fuel out of it to make it start to have some knock but still no o2 readings change under wot reguardless of the tune. I have checked the grounds on the back of the passenger side head, battery and still no changes. Also looked at the ecm for any loose wires, exc with no luck. I am using the same OTC monitor I have used for many years and have never seen this before on any of my cars.
Any ideas on what could be causing this?
It reads fine all the way until you hit wide open throttle then all of a sudden the O2 readings go to the basement with readings going from .790/.820 under 1/2 to 3/4 throttle to .03-.06 under wide open throttle. But still pulls fine and hard and has no knock. I have pulled enough fuel out of it to make it start to have some knock but still no o2 readings change under wot reguardless of the tune. I have checked the grounds on the back of the passenger side head, battery and still no changes. Also looked at the ecm for any loose wires, exc with no luck. I am using the same OTC monitor I have used for many years and have never seen this before on any of my cars.
Any ideas on what could be causing this?
