ARM Downpipes

[MTV10]

Hi Guys,

Looking for a little insight here. . .

Installed ARM DP's today. From what I've read on the forums, it is important to swap the post-cat O2 sensors from side to side during install. However, mechanic went ahead and followed ARM's instruction booklet, which states this is not necessary.

On the way home, car threw a CEL with the following codes:

P013B
P013D

I'm assuming I will need to buy a harness extender kit and have them swapped? Should I not go WOT in the meantime to avoid engine damage?

Any help is appreciated.

[HolyHell]

They absolutely do have to be swapped, i had the same issue. Once I swapped the codes went away, make sure to use quality harnesses and you might still have to use spacers.

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[MTV10]

Any issues driving over the next week as is?

[HolyHell]

The rear sensors shouldn't give you much of an issue. You'll be okay, just take it easy. The front sensors are the ones that will cause serious issues if left unattended.

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[mrdouble99]

if it's only the post O2 it shouldn't make any difference.

The code you have is slow response from the 2 post O2 sensor.

Did you try to disconnnect the battery for a reset of the ltft and stft ?

[qcrazy]

You need to swap them. Just unplug them until the extenders come. Less likely to cause damage if unplugged, rather then leaving them. I've seen a lot of this on cars I've been tuning. ARM is a joke for causing all of this confusion.

[MTV10]

These good?

https://www.parkautomotorsports.ca/collections/exhaust/products/usp035?variant=45283911182

[MTV10]

Reading some people's experience where the harness extender isn't even necessary...

Will tackle this tomorrow. Passenger side seems to be a PIA to access without a lift.

[HolyHell]

Reading some people's experience where the harness extender isn't even necessary...

Will tackle this tomorrow. Passenger side seems to be a PIA to access without a lift.Passenger side is doable from the wheel well but it is definitely a PITA, just be patient and stretch lol

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[MTV10]

Couldn't get access without a lift. Going to bring it to shop tomorrow and have them swapped.

For now, here's a cold start video:


https://www.youtube.com/watch?v=ngcKeu8DEo4

[mrdouble99]

dang, that's loud !

[MTV10]

Mechanic states harness extender is absolutely necessary.

[A665]

Sounds like.....um....NASCAR [o_o]

[MTV10]

Thank you, FedEx man.

[MTV10]

Alright, swapped O2 sensors side to side. Drove around all morning and all was good.

2 minutes from my house... CEL came back code P013D.

[HolyHell]

You might need some spacers for the rear sensors.

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[MTV10]

Spacers are installed.

[pnky_s6]

I have the codes, even with their CEL delete kit. I've been running these on stage 3 since January and zero issues and I hardly even notice the CEL anymore lol.

[5280AUDIS6]

I am currently dealing with this issue with brand new OEM O2 sensors and the O2 sensors extensions. I have ARM catless downpipes with the CEL spacers installed.https://www.rmeuropean.com/Products/4H0906262L-MFG14-V4627.aspx https://www.rmeuropean.com/Products/4H0906262M-MFG14-V4627.aspx

[MTV10]

Those spacers don't work. Getting custom a tune tomorrow.

[5280AUDIS6]

The spacers come with 2 different adapters a 60º "J" looking one and and a straight "I" adapter. I have tried using both adapters screwed together. This configuration just gave me P013B & P013D codes so not enough exhaust is being let in at idle since that's when my CEL turned back on. This weekend I will try just the single "J" adapter to see if it will let in just enough exhaust but not so much that it trips another code. If that doesn't work I will try the "I" spacer. ARM doesn't tell you these things and sometimes you just have to try different things and see if it works by trial and error. I am determined to get this figured out so I can create a write up and post it to this forum.

[qcrazy]

You should join the C7 Telegram group. Lots of experience on there with these ARM downpipes. No reason to do trial and error by yourself. Link posted in the Chatterbox.

https://www.audizine.com/forum/showthread.php/892970-C7-C7-5-Group-Chat

[MTV10]

Not going to make an account. What does it say?

[5280AUDIS6]

I was able to take off the "I" adapter off and leave the "J" adapter on and cleared the codes and drove it for 40 miles on the highway and in local traffic and no codes came up. I am going to drive it to work all week if it does not snow again (summer tires). Just need to get the I/M readiness, then off to emissions. I feel accomplished! I used a crowfoot wrench to get off the adapter since there is no room 7/8" because my metric set does not go up to 22MM and both sizes are close.

[viper04]

I was able to take off the "I" adapter off and leave the "J" adapter on and cleared the codes and drove it for 40 miles on the highway and in local traffic and no codes came up. I am going to drive it to work all week if it does not snow again (summer tires). Just need to get the I/M readiness, then off to emissions. I feel accomplished! I used a crowfoot wrench to get off the adapter since there is no room 7/8" because my metric set does not go up to 22MM and both sizes are close.

interesting Keep us posted!

[Vendetta44]

I was able to take off the "I" adapter off and leave the "J" adapter on and cleared the codes and drove it for 40 miles on the highway and in local traffic and no codes came up. I am going to drive it to work all week if it does not snow again (summer tires). Just need to get the I/M readiness, then off to emissions. I feel accomplished! I used a crowfoot wrench to get off the adapter since there is no room 7/8" because my metric set does not go up to 22MM and both sizes are close.How did this turn out? Currently in same boat

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[Vendetta44]

They absolutely do have to be swapped, i had the same issue. Once I swapped the codes went away, make sure to use quality harnesses and you might still have to use spacers.

Sent from my Pixel 5 using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)Both sensors on both sides need to be swapped or just both sensor 2's?

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[HolyHell]

Both sensors on both sides need to be swapped or just both sensor 2's?

Sent from my SM-S918U using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)Just the rear sensors, "downstream"

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[Vendetta44]

Just the rear sensors, "downstream"

Sent from my Pixel 5 using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)Im getting four faults total. One for each sensor. Front ones giving lamba faults. Will those go away after swapping the rears?

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[MTV10]

Swap them and you should be good.

[tylersund72]

Hey everyone,

I have a c7 s6 and I just recently upgraded to rs7 turbos, arm catted downpipes, and a few other things. I saw this forum post before I had the downpipes installed, and had them swap from side to side the post cat o2 sensors. I also put the o2 spacers that ARM offers to negate a check engine light since I live in an area that requires emissions yearly.

After about 10 miles of driving, I got 2 codes, p014b and p013f. The shop is currently closed, I plan on calling them as soon as they open to ensure it was in-fact the post cat o2 sensors that they swapped, but I believe those are the ones they did.

Any suggestions? Much appreciated.

[Vendetta44]

Hey everyone,

I have a c7 s6 and I just recently upgraded to rs7 turbos, arm catted downpipes, and a few other things. I saw this forum post before I had the downpipes installed, and had them swap from side to side the post cat o2 sensors. I also put the o2 spacers that ARM offers to negate a check engine light since I live in an area that requires emissions yearly.

After about 10 miles of driving, I got 2 codes, p014b and p013f. The shop is currently closed, I plan on calling them as soon as they open to ensure it was in-fact the post cat o2 sensors that they swapped, but I believe those are the ones they did.

Any suggestions? Much appreciated.With the spacers will need to remove the "I" part of the spacer and just use the "j" part. They are adjustable spacers but found that is best way for this platform.

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[tylersund72]

With the spacers will need to remove the "I" part of the spacer and just use the "j" part. They are adjustable spacers but found that is best way for this platform.

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Correct me if I'm wrong, I'm kind of a dummy when it comes to this stuff so I very well could be haha. But these are in the "J" form, correct?

https://www.flickr.com/photos/198869311@N03/53087074497/in/dateposted-public/
https://www.flickr.com/photos/198869311@N03/53087074497/in/dateposted-public/ Passenger side

https://www.flickr.com/photos/198869311@N03/53087638451/in/dateposted-public/
https://www.flickr.com/photos/198869311@N03/53087638451/in/dateposted-public/ Driver side

[Vendetta44]

Correct me if I'm wrong, I'm kind of a dummy when it comes to this stuff so I very well could be haha. But these are in the "J" form, correct?

https://www.flickr.com/photos/198869311@N03/53087074497/in/dateposted-public/
https://www.flickr.com/photos/198869311@N03/53087074497/in/dateposted-public/ Passenger side

https://www.flickr.com/photos/198869311@N03/53087638451/in/dateposted-public/
https://www.flickr.com/photos/198869311@N03/53087638451/in/dateposted-public/ Driver sideYes. J and then goes straight up. It's two pieces. You can get rid of the long part and just use the "j" part that is screwed into the downpipe.

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[tylersund72]

Yes. J and then goes straight up. It's two pieces. You can get rid of the long part and just use the "j" part that is screwed into the downpipe.

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Oh I see, thank you for the quick explanation, I really appreciate it!!

[Vendetta44]

Oh I see, thank you for the quick explanation, I really appreciate it!!No problem!

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[tylersund72]

No problem!

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Based on your knowledge, am I okay to drive it in the meantime till I get them adjusted, or should I take care of it asap? I read on this post about people talking about engine damage when it comes to the o2 sensors not being swapped, but this is a bit different I would think.

[Vendetta44]

Based on your knowledge, am I okay to drive it in the meantime till I get them adjusted, or should I take care of it asap? I read on this post about people talking about engine damage when it comes to the o2 sensors not being swapped, but this is a bit different I would think.Post cat ones perfectly fine to drive. If giving faults for pre cat ones then wouldn't recommend doing much driving

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[tylersund72]

Post cat ones perfectly fine to drive. If giving faults for pre cat ones then wouldn't recommend doing much driving

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Okay, perfect. Once again, appreciate the help! I'll keep an eye on the codes until I get them adjusted.

[tylersund72]

I’m getting a few new codes now. p2195, p2196, p2197 and p2198. Any ideas on these ones? These being upstream o2 sensor codes is more concerning to me.

[Vendetta44]

I’m getting a few new codes now. p2195, p2196, p2197 and p2198. Any ideas on these ones? These being upstream o2 sensor codes is more concerning to me.Your sure the post cat o2's are on the right side? Would need harness extensions if they are swapped as won't reach otherwise. Only ask bc I had upstream faults too until that was done. Didn't have access to a hoist so had shop do it and they did not swap the post cat ones bc in arms instructions says you don't need to when in fact you do so I did it myself couple days later and had faults for all four sensors even after clearing them after picking the car up

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[tylersund72]

Your sure the post cat o2's are on the right side? Would need harness extensions if they are swapped as won't reach otherwise. Only ask bc I had upstream faults too until that was done. Didn't have access to a hoist so had shop do it and they did not swap the post cat ones bc in arms instructions says you don't need to when in fact you do so I did it myself couple days later and had faults for all four sensors even after clearing them after picking the car up

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They have it stated in the notes that they swapped the sensors like I requested, but they must not have. They didn’t mention anything about a harness extension, from what I know it’s possible to do without the extension, but it’s a PITA. I’ll have to look at a diagram and see if they are in fact switched or not. I wasn’t having any issues at all with DTCs before I had the work done so I’m assuming they just aren’t swapped from side to side.


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[Vendetta44]

They have it stated in the notes that they swapped the sensors like I requested, but they must not have. They didn’t mention anything about a harness extension, from what I know it’s possible to do without the extension, but it’s a PITA. I’ll have to look at a diagram and see if they are in fact switched or not. I wasn’t having any issues at all with DTCs before I had the work done so I’m assuming they just aren’t swapped from side to side.


Sent from my iPhone using TapatalkYou should be able to tell if ya know what your looking for when look at the downpipes. Drivers side o2 harness is right on top on the drivers side of the engine and needs to plug into the pass side post cat o2. It would be a pain try get that to reach without extensions. Pass side plug is alot harder to get to as it's bottom of the pass side of the engine.

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[tylersund72]

You should be able to tell if ya know what your looking for when look at the downpipes. Drivers side o2 harness is right on top on the drivers side of the engine and needs to plug into the pass side post cat o2. It would be a pain try get that to reach without extensions. Pass side plug is alot harder to get to as it's bottom of the pass side of the engine.

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From how you explained it, looks like they didn’t get swapped and that’s my issue. I justbought a harness extender, I’ll get that on asap. Thanks for the help once again! :)

[Vendetta44]

From how you explained it, looks like they didn’t get swapped and that’s my issue. I justbought a harness extender, I’ll get that on asap. Thanks for the help once again! :)Will need one for both sides. Easiest way to get to pass side o2 plug is through the wheel well. Will need to pull back wheel well trim and remove heat sheild to left of axle and then should be able to reach up in their to unplug and plug extension harness in

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[tylersund72]

Will need one for both sides. Easiest way to get to pass side o2 plug is through the wheel well. Will need to pull back wheel well trim and remove heat sheild to left of axle and then should be able to reach up in their to unplug and plug extension harness in

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I got 2 of them*. English is hard sometimes haha. Got these off USP https://www.uspmotorsports.com/product/usp-secondary-oxygen-sensor-extension-harness-75007028?gclid=Cj0KCQjwoK2mBhDzARIsADGbjeoxcg-S4aDjW_pijbiCPoc1azs7OOZR4W3zauIPHYti58snFTqHkSAaA i8fEALw_wcB Appreciate the tips, I’ll get them switched as soon as the harnesses come in.


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[Vendetta44]

I got 2 of them*. English is hard sometimes haha. Got these off USP https://www.uspmotorsports.com/product/usp-secondary-oxygen-sensor-extension-harness-75007028?gclid=Cj0KCQjwoK2mBhDzARIsADGbjeoxcg-S4aDjW_pijbiCPoc1azs7OOZR4W3zauIPHYti58snFTqHkSAaA i8fEALw_wcB Appreciate the tips, I’ll get them switched as soon as the harnesses come in.


Sent from my iPhone using TapatalkPerfect [emoji108]

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[CrazyFeng]

I'm about to upgrade ARM's catted downpipes and JHM's stage 2, but I have a few questions:
1. Do I need to buy an oxygen sensor extension harness?
2. Do I need swap two sensors?
3. Do I need to use spacers?

Thanks everyone.

[Vendetta44]

I'm about to upgrade ARM's catted downpipes and JHM's stage 2, but I have a few questions:
1. Do I need to buy an oxygen sensor extension harness?
2. Do I need swap two sensors?
3. Do I need to use spacers?

Thanks everyone.Does jhm offer the option to code out post cat o2's? I had RS4 back in the day that I tuned with JHM ots tune and that was an option that I took advantage of. If able to code out then won't need the spacers but recommend getting the extensions and swapping still

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[tylersund72]

I'm about to upgrade ARM's catted downpipes and JHM's stage 2, but I have a few questions:
1. Do I need to buy an oxygen sensor extension harness?
2. Do I need swap two sensors?
3. Do I need to use spacers?

Thanks everyone.

Like Vendetta said, you don’t need spacers if your tune will code out the CEL. The reason I got spacers, is cause I live in an area that requires emissions/smog inspections. If my CEL is on for an inefficient cat, I fail emissions. And if my tune codes out the CEL, I also fail and get flagged. O2 spacers are technically a “tamper”, but I can get away with it easier than the other 2 options. I read somewhere that someone used the catted downpipes without spacers and went a while without a CEL, I just didn’t want to take the risk, and went ahead with the spacers.

If you swap the downstream o2 sensors, you basically require the extension harnesses. And that is something you will want to do to avoid engine damage/DTCs.


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[CrazyFeng]

Does jhm offer the option to code out post cat o2's? I had RS4 back in the day that I tuned with JHM ots tune and that was an option that I took advantage of. If able to code out then won't need the spacers but recommend getting the extensions and swapping still

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Thanks a lot. I will buy secondary oxygen sensor extension harness.

- - - Updated - - -


Like Vendetta said, you don’t need spacers if your tune will code out the CEL. The reason I got spacers, is cause I live in an area that requires emissions/smog inspections. If my CEL is on for an inefficient cat, I fail emissions. And if my tune codes out the CEL, I also fail and get flagged. O2 spacers are technically a “tamper”, but I can get away with it easier than the other 2 options. I read somewhere that someone used the catted downpipes without spacers and went a while without a CEL, I just didn’t want to take the risk, and went ahead with the spacers.

If you swap the downstream o2 sensors, you basically require the extension harnesses. And that is something you will want to do to avoid engine damage/DTCs.


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Thanks for the answer, your information is very helpful to me.

[tylersund72]

Hey everyone, having some more issues with these downpipes and was hoping to get some ideas.

I've made some posts in this thread with some other issues, but I am experiencing something else now, and I haven't been able to get any answers on it.

Car info/upgrades (in-case it could be relevant) 2014 S6 - RS7 turbos, CTS intakes, CTS intercooler, ARM catted downpipes, JHM turbo inlet pipes, SRM TCU tune, DS1 Stage 3 ECU tune.

I have the catted ARM downpipes installed on my c7 s6. I have the o2 extenders that ARM offered with their downpipes, and I am using only the "J" part of the spacers. I am getting P013B and P013D intermittently, which isn't concerning to me since they are downstream sensor codes. But I am also getting codes such as P2197 and P2198, which are much more concerning to me with them being upstream sensor codes. Any ideas on these? I have already swapped the downstream o2 sensors with quality extender harnesses. From the research I've stumbled upon, it seems like 99% of the people experiencing this issue, resolve it by swapping those downstream sensors.