i was wondering if i needed o2 sensors. I think their the originals i have 110000 miles now. My car runs great right now but in my freescan logs the o2 left and right drop to 0 multiple times. The high the reading go is to .98. Do i need new ones even though my car is runnign good?


thanks

 

ttt

 

I have the miles in the sig. and things are still good.

It seems I remember an occasional 0 not many though, and high .9xxs.

the average should be around .400, and when you WOT should be relatively steady at whatever you set them. Maybe you have the beginings of some trouble or EMI from bad plug wires or something. Seems odd that both would go bad at the same time, or indicative of a more global problem.

Check with Injuneer's tuning document to verify the average of .400. I haven't worked with my car in a while, it's been a long winter.

 

In closed loop, the sensors should be moving back and forth up to 9 times per second. Seeing numbers over the full range of 0xx to 9xx is not unusual.... fairly normal. The average, over a reasonable period of time, in closed loop should be about 450mV.

 

when does the car go into closed loop?

 

There are several criteria that must be met for closed loop operation. Please read, read again, and then study Injuneer's tuning document. I believe he also has links to other tuning documents on his site. You'll be off to an excellent start.