O2 Sensor Tuning - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Mertz · 11-10-2009, 12:04 PM

I installed a wideband (Standard SG-12) O2 sensor in my header to try to tune in my Q-jet. It warmed up fine but when I went for a drive it went to negative volts. It started out at -50mv then went up to -140mv at cruise after some more driving. If I put it under load it would go to 770mv and then drop back down to -140mv. Warmed up and in park in the driveway after the trip it went to 820mv and gradually dropped. I didn't waight to see how far it would drop. I rev'd it a little and it goes down to almost zero and climbs back up to 820 before dropping again.

The exhaust is good with no leaks. I have not been able to find a vacuum leak but I think that might be causing the problem. Anybody had this same experience?

11-10-2009, 12:04 PM	#1
Mertz Registered User Join Date: Aug 2007 Location: Reardan, WA Posts: 132	O2 Sensor Tuning I installed a wideband (Standard SG-12) O2 sensor in my header to try to tune in my Q-jet. It warmed up fine but when I went for a drive it went to negative volts. It started out at -50mv then went up to -140mv at cruise after some more driving. If I put it under load it would go to 770mv and then drop back down to -140mv. Warmed up and in park in the driveway after the trip it went to 820mv and gradually dropped. I didn't waight to see how far it would drop. I rev'd it a little and it goes down to almost zero and climbs back up to 820 before dropping again. The exhaust is good with no leaks. I have not been able to find a vacuum leak but I think that might be causing the problem. Anybody had this same experience?



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.