Lead Poisoning

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Bill Dedman

Bill Dedman

bill dedman
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Can someone tell me how to know when an Oxygen sensor is going bad due to lead contamination from leaded fuel?

I have an F.A.S.T. O2 sensor and it sticks on one number under any circumstances... It should be changing, but it won't.

I bought another sensor for it, but would like to know what to look for when this one goes bad.

Unleaded race fuel is $$$$$$$$$$$$$$$$$$$$$$disgust
 
It will stop switching
You cannot use leaded fuel with an 02 sensor ,also avoid using silicone, either will coat the sensor causing it to fail
 
This IS narrow band, right? If it is reading too rich, it MIGHT just be way too rich.
 
If its a Bosch (most are) then that will be your problem! They tend to go bad pretty fast. The way that AEM told me to check it was to remove the sensor and plug it back up to the harness, soak a rag with gas and wrap it around the sensor. It should peg the gauge pig rich. If not, its faulty.

Most AFR gauges will show 14.7 when the sensor is bad or inoperable and won't change under any condition.
 
william said:
It will stop switching
You cannot use leaded fuel with an 02 sensor ,also avoid using silicone, either will coat the sensor causing it to fail
Click to expand...

The leaded fuel I was using was "LL100" av gas. LL stands for "low-lead," supposedly, but I have been to that that is a mis-nomer; that LL100 has a LOT of lead in it!

I am trying to set up the A/F ratio in a boosted application and detonation is my nemesis; it will KILL my engine, especially if it happens under boost.

What do you suggest I do, to get a reading when using 15 pounds of boost; no-lead racing gas? That stuff is like GOLD...

Is that my only option? My engine has an alcohol spray (Snowperformance Boost Cooler) and an air-to-air intercooler of an appropriate size.
 
CUUDAK said:
If its a Bosch (most are) then that will be your problem! They tend to go bad pretty fast. The way that AEM told me to check it was to remove the sensor and plug it back up to the harness, soak a rag with gas and wrap it around the sensor. It should peg the gauge pig rich. If not, its faulty.

Most AFR gauges will show 14.7 when the sensor is bad or inoperable and won't change under any condition.
Click to expand...

Thanks for the information. I don't know who the manufacturer is, but the unit it's in is sold by F.A.S.T.
 
67Dart273 said:
This IS narrow band, right? If it is reading too rich, it MIGHT just be way too rich.
Click to expand...

It says on the package it came in that it is a wideband, data-logging, A/F ratio meter and is sold by F.A.S.T. in Memphis, TN

It was stuck on 9.5...
 
william said:
It will stop switching
You cannot use leaded fuel with an 02 sensor ,also avoid using silicone, either will coat the sensor causing it to fail
Click to expand...


I understand bout the lead-poisioning, but I don't know what you're referring to when you warn against "silicone."

What "silicone?"

Enlighten me.... please.:glasses7:
 
Bill, the silicone would come from many of the different gasket glues and such. Even if you used sealant on your cold side of your turbo plumbing this can eventually migrate through your exhaust to the sensor. I used to do surface analysis for the electronics industry where silicone would wreak havoc with any kind of plating process and you would be amazed how easily and how well silicon migrates to other areas from the area it was applied. Still my money is on the lead in the gas. John
 
RVT sealant (silicone)
Don't use it on the intake or exhaust .They claim it's o2 and cat safe but still causes failures.
You can use it to seal oil or coolant but use it sparingly.
And yes the leaded fuel would kill it.
 
crazyjjk said:
Bill, the silicone would come from many of the different gasket glues and such. Even if you used sealant on your cold side of your turbo plumbing this can eventually migrate through your exhaust to the sensor. I used to do surface analysis for the electronics industry where silicone would wreak havoc with any kind of plating process and you would be amazed how easily and how well silicon migrates to other areas from the area it was applied. Still my money is on the lead in the gas. John
Click to expand...

Okay; thanks to you and William for the explanation.

I haven't used any silicone on this car... none. And after this info, probably won't..
 
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