O2 Sensors

[sssammm]

info needed

2017 ACR, where are the secondary O2 sensors located on the exhaust,
am i right to believe that the are right at the back just before the exit?

thanks
sam

[AZTVR]

2017 ACR, where are the secondary O2 sensors located on the exhaust,
am i right to believe that the are right at the back just before the exit?

I would look for them between the catalytic converters. (The following is a photo of 2014 OEM config)

https://driveviper.com/forums/thread...ll=1#post93969Gen 5 stock exhaust.jpg

[Steve M]

Secondary O2 sensors are after the first cat, so pretty much right in front of your feet.

[sssammm]

apparently not on the ACR, they are on the bend of the tailpipe ???

[ViperTony]

apparently not on the ACR, they are on the bend of the tailpipe ???

No, the sensors are definitely NOT in the bend of the tailpipe on the ACR. Look at AZTVR's photo above.

[AZTVR]

apparently not on the ACR, they are on the bend of the tailpipe ???

You may be thinking about a post or photo of a Bellanger configuration.

[ViperTony]

You may be thinking about a post or photo of a Bellanger configuration.

On the Belanger system, the downstream O2's are not in the tail pipe either unless Lou changed the design over the last two years.

[AZTVR]

On the Belanger system, the downstream O2's are not in the tail pipe either unless Lou changed the design over the last two years.

I was recalling post #15 in a thread from earlier this week, and the thread also had a photo to show where the bungs should be now. https://driveviper.com/forums/thread...l=1#post421851

[sssammm]

[ATTACH=CONFIG]45790[/ATTACH
Rear bung position now

[ViperGeorge]

[ATTACH=CONFIG]45790[/ATTACH
Rear bung position now

I have had my 2017 ACR-E exhaust apart and there is definitely no bung by the tailpipe.

[Steve M]

I have had my 2017 ACR-E exhaust apart and there is definitely no bung by the tailpipe.

Stock, or Belanger like is being discussed in this thread?

[ViperGeorge]

Stock, or Belanger like is being discussed in this thread?

I have ARH headers, high flow cats with stock cat back exhaust.

[ViperTony]

[ATTACH=CONFIG]45790[/ATTACH
Rear bung position now

You have the new design. They didn't provide O2 extensions?

[sssammm]

I got them for the back, but nothing for the front, in
the new design the bung has been moved down to the collector from where it used to be in the tube
12" too short now, and im getting told that i dont need them,

[Steve M]

I have ARH headers, high flow cats with stock cat back exhaust.

I think that's where everyone is getting confused. Too many different possible configurations.

For stock exhaust manifolds with stock cats, the primary O2 sensor is in the collector of the exhaust manifold (close to the engine block), and the secondary O2 sensor sits after the first cat, pretty much right in front of where your feet would go.

For cars with headers, I've seen primary O2 sensor locations vary from one of the primary tubes (close to the engine block) all the way to in the collector (which would put them pretty much right in front of your feet). Secondary O2 sensor bungs are either non-existent, or somewhere around the corner of the bend before the exhaust tubing meets the muffler.

The issue that has thrown folks for a loop with the secondary O2 sensors only applies to the Belanger muffler/resonator setup. Belanger moved the secondary O2 sensor location to the exhaust tips. This is a clever trick to get the secondary O2 sensors closer to fresh oxygen, which would skew the O2 sensor readings, essentially making the PCM think the catalytic converters are doing a better job than they actually are (which would keep it from throwing catalytic converter efficiency codes). Again, this only applies to the Belanger muffler + exhaust tip combo - if you are running stock mufflers, it does not.

The other variable is whether or not the secondary O2 sensors are even needed. That answer is simple - if you are running the stock PCM with the stock calibration, you need fully functioning secondary O2 sensors to keep the PCM from throwing codes. If you are using anything else (like the Arrow PCM), they aren't needed. In the case of HPTuners, you can make the choice as to whether or not you keep them.

The secondary O2 sensor codes are only a nuisance - they do not affect engine operation, specifically closed loop fueling adjustments (trims). They are only used to assess catalytic converter efficiency.

[ViperGeorge]

I think that's where everyone is getting confused. Too many different possible configurations.

For stock exhaust manifolds with stock cats, the primary O2 sensor is in the collector of the exhaust manifold (close to the engine block), and the secondary O2 sensor sits after the first cat, pretty much right in front of where your feet would go.

For cars with headers, I've seen primary O2 sensor locations vary from one of the primary tubes (close to the engine block) all the way to in the collector (which would put them pretty much right in front of your feet). Secondary O2 sensor bungs are either non-existent, or somewhere around the corner of the bend before the exhaust tubing meets the muffler.

The issue that has thrown folks for a loop with the secondary O2 sensors only applies to the Belanger muffler/resonator setup. Belanger moved the secondary O2 sensor location to the exhaust tips. This is a clever trick to get the secondary O2 sensors closer to fresh oxygen, which would skew the O2 sensor readings, essentially making the PCM think the catalytic converters are doing a better job than they actually are (which would keep it from throwing catalytic converter efficiency codes). Again, this only applies to the Belanger muffler + exhaust tip combo - if you are running stock mufflers, it does not.

The other variable is whether or not the secondary O2 sensors are even needed. That answer is simple - if you are running the stock PCM with the stock calibration, you need fully functioning secondary O2 sensors to keep the PCM from throwing codes. If you are using anything else (like the Arrow PCM), they aren't needed. In the case of HPTuners, you can make the choice as to whether or not you keep them.

The secondary O2 sensor codes are only a nuisance - they do not affect engine operation, specifically closed loop fueling adjustments (trims). They are only used to assess catalytic converter efficiency.

I think the confusion resulted from the OP's failure to state which exhaust he was asking about. See his first post. Without specifying I assumed he was talking about the OEM exhaust.

[Steve M]

I think the confusion resulted from the OP's failure to state which exhaust he was asking about. See his first post. Without specifying I assumed he was talking about the OEM exhaust.

Yeah, that too.

[sssammm]

yes i agree, at first when i got my Belanger, the secondary was by the tip, i was just querying this, but since installing the Belangers, the primary bung has been moved down from the tube, where the older ones used to be, down to the collector, so my primary O2 sensors are now 12" too short

[Fatboy 18]

Yes, Sam has just purchased a new complete Belanger System for his car and is trying to work out the positioning of the O2 Sensors.

It seems O2 extension cables are needed, Anyone know of a supplier? (Don't want to cut into the existing wires).

The car is 100% Stock, (no Arrow or PCM tunes).

[ViperTony]

I found O2 sensor extensions for my Gen2 years ago when I moved the upstream O2 sensor to the collector in those Belanger headers. I don't know if the supplier makes an extension for the GenV but worth a look. Caspers Electronics is the manufacturer. Summit sells them maybe they have one for the GenV. https://www.summitracing.com/search/...s?fr=part-type

[Fatboy 18]

I found O2 sensor extensions for my Gen2 years ago when I moved the upstream O2 sensor to the collector in those Belanger headers. I don't know if the supplier makes an extension for the GenV but worth a look. Caspers Electronics is the manufacturer. Summit sells them maybe they have one for the GenV. https://www.summitracing.com/search/...s?fr=part-type

Thanks Tony

[ViperTony]

Thanks Tony

I'd also call Lou Belanger too...he must know a source. Dan Lesser, Dan Craigan, JonB, etc. I'm sure they've all run into similar situations requiring the need for extensions.

Also it appears Amazon has them.... https://www.amazon.com/2014-2017-Che...3981073&sr=8-3

[ViperGeorge]

ARH headers on my Gen 4 required extensions but they were provided by ARH. The plugs and sensors are different on a Gen 5 though so the Gen 4 extensions wouldn't work.

By the way, if you are running the Mopar Controller you don't need the rear sensors just install a threaded plug in the bung.

[sssammm]

Thanks Tony,
Just ordered