AEM o2 sensor

[eric8]

Anyone see an issue with leaving the UEGO sensor screwed in to the exhaust bung, but unplugged?  My o2 sensor is in a very difficult area to access, and it'd be much easier to just plug in the gauge to the sensor pigtail when I want to use it.

[Belgian1979]

It's not good for them to be in the exhaust unheated. Moisture and carbon collects on them.

[eric8]

Interesting. I emailed AEM and they told me something similar, saying an unheated sensor in the exhaust stream could "foul."

I have a set of 87 C10 truck cast iron manifolds on a 383. I have my AEM o2 sensor screwed into the factory GM bung on the manifold, which is in the driver's side manifold's collector just downstream of the exhaust ports.

I'm playing devil's advocate here, but how does the tiny 22 gauge wire powering the AEM sensor get it hotter than the temps it would see unheated inside a cast iron manifold, right off of the exhaust ports?

[Monzsta]

Interesting. I emailed AEM and they told me something similar, saying an unheated sensor in the exhaust stream could "foul."

I have a set of 87 C10 truck cast iron manifolds on a 383. I have my AEM o2 sensor screwed into the factory GM bung on the manifold, which is in the driver's side manifold's collector just downstream of the exhaust ports.

I'm playing devil's advocate here, but how does the tiny 22 gauge wire powering the AEM sensor get it hotter than the temps it would see unheated inside a cast iron manifold, right off of the exhaust ports?

The heating element gets the ceramic to 1400 degrees so the sensor stays clean, like a spark plug. Without the heater running at least occasionally carbon will foul the sensor.

[Belgian1979]

I broke several in mine and the reason was it started up too fast while the engine was still not running. So the first amount of moisture ended up on them and the heat of the wire with the effect of water broke the ceramic in them. I exchanged about 3 of those before I figured it out. I know have teh sensor start about 10 seconds after the engine starts running. So far no issues.