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Discussion Starter · #1 ·
Why is there a bung for an o2 sensor on my driver manifold?

Did they know they were gonna add something later?

Do later model tacomas have one there? I have a 96.
 

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'95-'96 was the first of obd2(on board diagnostics second generation).Each bank of cylinders must have an o2 sensor if it's a v6.That would mean you should have 3 o2 sensors,one in each exhaust manifold and one after the cat.
 

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'95-'96 was the first of obd2(on board diagnostics second generation).Each bank of cylinders must have an o2 sensor if it's a v6.That would mean you should have 3 o2 sensors,one in each exhaust manifold and one after the cat.
Sorry charlie. Every V6 I've seen has 2 O2 sensors. First is after the collector, but before the cat. On the newer models, this is an air/fuel sensor. Second is the traditional O2 sensor located after the cat.
 

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My 97 V6 has EGR and there is a port on the driver's side manifold and a tube that runs around the back of the engine to.....an EGR valve.

I wonder if the EGR contributes to ping on SC'd engines?
 

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I wonder if the EGR contributes to ping on SC'd engines?
Its main purpose is to lower peak combustion temps in order to reduce NOx emissions, however, by introducing oxygen depleted exhaust gasses to the intake charge it also results in an effectively richer mix. The combination of lower combustion temps and a richer mix results in an intake charge that is less likely to suffer detonation.
 

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Sorry charlie. Every V6 I've seen has 2 O2 sensors. First is after the collector, but before the cat. On the newer models, this is an air/fuel sensor. Second is the traditional O2 sensor located after the cat.
You are correct,i forgot the manifold for the left side runs over the bell housing area,no room for another 02.I don't see too many of those to work on,mostly american junk.And mine is a 4cyl.sorry for the bad info!
 

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Its main purpose is to lower peak combustion temps in order to reduce NOx emissions, however, by introducing oxygen depleted exhaust gasses to the intake charge it also results in an effectively richer mix. The combination of lower combustion temps and a richer mix results in an intake charge that is less likely to suffer detonation.
Thanks for the explanation, I was thinking that bringing in already heated air (exhaust) would have the same effects as increased intake temps.
 

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You are correct,i forgot the manifold for the left side runs over the bell housing area,no room for another 02.I don't see too many of those to work on,mostly american junk.And mine is a 4cyl.sorry for the bad info!

Actually you were right, but for some reason on the 3.4 there is only one sensor before the cat. Here is the supporting information from Toyota http://www.autoshop101.com/forms/h37.pdf
 

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Discussion Starter · #10 ·
So the census says, Bung is for future EGR system.

So then, Back to my original topic. Since Toyota knew there was going to be a new system introduced soon after, why not introduce it imediately?

What kind of efficiency changes would this new EGR system make? Doesn't my 96 engine have an EGR system? If so what changed?
 

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So the census says, Bung is for future EGR system.

So then, Back to my original topic. Since Toyota knew there was going to be a new system introduced soon after, why not introduce it imediately?

What kind of efficiency changes would this new EGR system make? Doesn't my 96 engine have an EGR system? If so what changed?
Actually, not all models have an EGR system. All California emission models had them, but the Federal spec models didn't always have all that additional smog junk.
 

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I do know that when TRD first put the SC on the market, they said it WAS NOT suitable for trucks with EGR. You can take that for whatever it's worth.
 

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I do know that when TRD first put the SC on the market, they said it WAS NOT suitable for trucks with EGR. You can take that for whatever it's worth.
I concur, I have both....
 
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