o2 sensor poisoning

[Riptide]

I have a 2014 mustang. I recently removed the midpipe from the car and installed two oxygen sensor j style defoulers. The purpose of these devices is to pull the sensor out of the stream for emissions issues.

https://www.summitracing.com/parts/vpe-11619

These defoulers have "jets" or pills clipped into them. I used permatex high temp red 81160 around the pill to keep it from rattling.

These oxygen sensors are close to this rtv and are also upstream directly from it. I am now reading that this is not safe to use with them. Not a real happy camper about this. I had no idea and there was nothing on the tube stating not safe for sensors. I have already put 50 miles on the car since the install.

How big of a deal is this? This area while close to the sensors is post combustion. I'm not sure if this makes a difference or not.

 

[bdcardinal]

Why don't you just use a tune from like Shawn at AED and turn the rear sensors off? Their only purpose is to monitor catalyst efficiency.

 

[Riptide]

Because I need to pass ODB2 emissions. The monitors won't complete with the sensors shut off.

 

[bdcardinal]

I've never been a fan of the J style non-foulers. Stacking 2 of the standard ones seems to work better, plus there is room between the exhaust and the MT-82 for it to work.

 

[Riptide]

It is a 6R80 car and the standard ones (non j style) don't clear the transmission pan with the sensor threaded in. Tried those already.

 

[Trav]

Not a problem the 81160 is sensor safe. If its working don't worry about it.

Quote:
excellent torque retention and hi-temp, sensor-safe properties

 

[Riptide]

Where are you seeing that? The sensor safe stuff I thought was the orange 81422.

 

[Trav]

Most major brand RTV is sensor safe today. This is one link, lots of others that all say the same thing. Call Permatex if you are still concerned. (860) 543-7500

http://www.truckpartshq.com/permatex-81160-high-temp-red-rtv-silicone-gasket-3-oz/

 

[Trav]

It has OEM approved right on the package, manufacturers wont approve an RTV that could damage any sensor.

 

[Riptide]

The situation is confused.

It does say OEM specified on the packaging. And yet they make a whole other part number for "sensor safe". And if you look at the amazon page for the red stuff you can see in the description it states sensor safe properties. But wait. Scroll down on the same page and you can see it says No for sensor safe in the table under the directions.
https://www.amazon.com/Permatex-81160-High-Temp-Silicone-Gasket/dp/B0002UEN1A

I am going to have to call them and speak with a tech and hope I get someone who knows what they are talking about.

I don't know how long it takes to poison an O2 sensor. I have read it can happen very quickly. 50 miles on the car already. I wish I knew how to data log the narrow band O2 sensors and verify they are still working.

 

[GMBoy]

Who cares if they are poisoned? They will just read slower and even - which reports good cats to the ECM. You can defeat the rear o2 by using RTV to kill them or the spark plug non-foulers. You just did both. The rear sensors do nothing for drivability anyhow. Just drive it.

 

[Riptide]

I could try that but I have no guarantee it would achieve the result I need. I'd rather not ruin a couple expensive sensors. I can't contest that by ruining them there is a possibility the monitors might pass. That said I've read of people who had poisoned their sensors and the result was a CEL. Doubtful monitors would pass in that situation. Who knows.

I called permatex this morning. The tech told me I used the wrong stuff and this is not sensor safe. I pulled the midpipe and removed the defoulers and am letting some of the copper high temp sensor safe stuff set up before reinstalling.

 

[Trav]

Strange they recommend it for valve covers and not being sensor safe, maybe a textbook answer maybe not I have no idea but it doesn't sound right, it could be that its so close to the sensor. Anyway you used the stuff they recommend now.

 

[Riptide]

Well my pride is damaged but thankfully that is it.

Done this many times before with no issue. Had the front end up sitting on ramps. Was lifting the rear end up with a floor jack. Somehow this ended up pulling the front end back far enough the car rolled right down the ramps. If I hadn't left the garage door open the car would've went right through it. I laid it down quick as I could and the brake was set so it stopped. No damage that I can tell to anything.

Lucked out. Next time I have the front on those ramps I want someone on the brake when I lift up the rear end. That should keep this from happening ever again.