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Discussion Starter #1
Doin some PM, I found one Oxygen Sensor on the firewall under the coilpack(getting replaced), where is the other ones at?

Just one there at the Y pipe and one after the Cat Im assuming?
 

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Definitely not 4, no FWD impala has 4. Either 2 or 3 depending on engine and year. One after cat, and either one or two before cat
 

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For a 2008 3.9, I'm pretty certain there are three sensors. I *believe* they are: Bank 1, Sensor 1 and Bank 2, Sensor 1 are both right by the engine block and Bank 1, Sensor 2 is downstream of the cat. Could be wrong, but I think that's how it is.

Hope this helps!
 

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Discussion Starter #4 (Edited)
2006. 3.9.

Lol... Well, the block goes around the whole engine bay.

I don't even see any wires for a sensor on the radiator side manifold. It goes back into a Y pipe that connects the two exhaust manifolds. One sensor for both "banks" is all I can find.

You can trick the one after the CAT if you want. We used to do it for deleting the CAT's. Put an ANTI-FOWLER insert. Its used for spark plugs to lift them out of the combustion chamber so they don't fowl out quick(if you have those problems.) O2 Sensors and Spark plugs use the same threads. The spark plug screws into the insert. It lifts it out of the flow. The O2 Sensor is the same way. Its still hooked up, just no flow across it to sniff. So it cant throw a code that way.

For off-road use only of course :)

Thanks Y'all!!
 

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2006. 3.9.

Lol... Well, the block goes around the whole engine bay.

I don't even see any wires for a sensor on the radiator side manifold. It goes back into a Y pipe that connects the two exhaust manifolds. One sensor for both "banks" is all I can find.

You can trick the one after the CAT if you want. We used to do it for deleting the CAT's. Put an ANTI-FOWLER insert. Its used for spark plugs to lift them out of the combustion chamber so they don't fowl out quick(if you have those problems.) O2 Sensors and Spark plugs use the same threads. The spark plug screws into the insert. It lifts it out of the flow. The O2 Sensor is the same way. Its still hooked up, just no flow across it to sniff. So it cant throw a code that way.

For off-road use only of course :)

Thanks Y'all!!
Yup, you are correct 2006 would only have 2. Sensor 1 in the raer manifold assembly before the flange for converter, , sensor 2 post converter.


As far as the antifouler trick...it works on some vehicles. starting in 2005-2007 is when it really starts to potentially not work. As the ECMs got more advanced they were able to monitor the sensors more carefully and determine if the information they were giving back was "rational" not just "good" It used to be if the normal range for a sensor was say 1-10, anything in there was good....didnt matter if it was stuck at 1.1, or only ever went betewn 4.5-7, if it was in range it was good. Now there are activity and performance codes.

This car will set a P0140 for insufficient sensor 2 activity. so if the sensor is too isolated from the exhaust stream and doesnt fluctuate enough it will still set a code. You can do things like start start to modify the size of the opening in the antifoul device, and get angled adapters to try to mechanically trick the ECM, but be aware it may not be possible and could require a tune, especially if youre trying to hide having no cat. trying to make up for a low cell count aftermarket cat may have better results. But with newer gen ECMs a tune is often the only recourse.
 

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Discussion Starter #6
Wow, what a PITA.... Cant get it out. Correct socket. MAP Gas Torch. SOB won't budge.. 3hrs now. No room for leverage/right angle, etc. What a sh**head design.

I guess the manifold will have to come off once it goes bad, I ain't messing with it until I get a Check Engine Light.
 

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were you replacing for maintenance?

only mentioning it because you didnt, but get the thing really hot, and then soak it down with something like PB Blaster or similar corroded fastener chemical release. I have excellent luck with this tactic. Soak it until the lubricant cools the area enough that its cool enough to touch without burninging yourself and until additional sprays of product dont cause steam. BE CAREFUL have a fire extinguisher handy
 

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Wow, what a PITA.... Cant get it out. Correct socket. MAP Gas Torch. SOB won't budge.. 3hrs now. No room for leverage/right angle, etc. What a sh**head design.

I guess the manifold will have to come off once it goes bad, I ain't messing with it until I get a Check Engine Light.
A trick that used to work kinda nice was heat the area of exposed threads with map torch to it is glowing red use a crayon and push it on to the exposed threaded area. now grab an adult beverage of choice allowing the area to cool. with the use of a wrench or socket the sensor should come loose. the crayon will burn off.
An older gentleman shared this trick with me and i am just passing it along. It works like a champ.
 
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