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Losing Wideband O2 Sensors

S

Silver GTP

New member
I have a PLX-AFR and I've had 2 sensors die in less than 4 months. PLX does not warranty sensors so I'm eating the cost of these. Anybody else had problems like this? I have it mounted about 4 or 5 inches downstream from the narrowband O2 so I don't think the position should be burning them out. Any ideas?
 


01gpgt01 said:
how rich are you running?
Click to expand...

14.7:1 under normal conditions. 11.9:1 at WOT. I did have a few weeks after the cam install at the end of Dec that I had to work on the cold start fueling. It was running really rich for the first 10-20 seconds until settling in at 14.7:1. I know it's supposed to do that, but after the cam it got excessive. It is much better now.

My drive to work is only about 6 miles. You think short trips like that could affect the life of the sensor?
 


I would probably guess there is some issues with the way it is mounted.

Make sure that it is mounted with the wiring end pointed up in the air as much as possible (GM put that factory Ubend in for a reason). Other than that, there is no reason for it other than a rich idle.
 
I've been exchanging e-mails with tech support at PLX. They recommend at least 24" downstream from the block for a supercharged car, mount the sensor in the top 1/3 of the pipe and point the tip of the sensor about 15 degrees downstream. I'm not quite 24" and I told them I couldn't mount it in the top 1/3 without cutting a hole in my floor or hanging my exhaust low off the bottom of the car. They replied that it was just a recommendation and to mount it as close to the top as possible. They also said it could be mounted after the cat, but that doesn't make sense to me how the reading would be worth anything after the cat. I'm going to weld in another bung a couple inches in front of the cat to give me the 24" minimum and give it the 15 degree angle the suggest. As far as being rich at idle, the narrowband and wideband would both have to be wrong for that to be happening. The only time it is running rich is at a cold start like it is supposed to.
 
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