986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Please confirm my diagnosis of one bad O2 sensor

Timbert · 12-25-2015, 04:01 PM

Mig, thanks and my situation occurs when fully warmed up: no voltage swings from O2 sensors. The idle is smooth and I've just driven it pretty gently over the last 300 miles or so and it seems fine. I just fixed a vacuum leak at the J-tube by sealing it with new o-rings from dealership and some small amount of blue RTV. Also turns out there's an O2 sensor relay to check as well as voltage to the sensors. Tomorrow I'll get the multimeter back out and check the outputs at the DME per the factory manual, as well as the wiring and connectors on the O2 circuit.

Again, when I put in two new front O2 sensors a month ago I got good voltage swings and now nothing...

12-25-2015, 04:01 PM	#8
Timbert Registered User Join Date: Sep 2015 Location: Phoenix Posts: 15	Mig, thanks and my situation occurs when fully warmed up: no voltage swings from O2 sensors. The idle is smooth and I've just driven it pretty gently over the last 300 miles or so and it seems fine. I just fixed a vacuum leak at the J-tube by sealing it with new o-rings from dealership and some small amount of blue RTV. Also turns out there's an O2 sensor relay to check as well as voltage to the sensors. Tomorrow I'll get the multimeter back out and check the outputs at the DME per the factory manual, as well as the wiring and connectors on the O2 circuit. Again, when I put in two new front O2 sensors a month ago I got good voltage swings and now nothing... Last edited by Timbert; 12-26-2015 at 09:22 AM.