RS3 8Y OPF and Cat Delete

[rs3_snowflake]

Hi, in a few days I will mount a 200 cell miltek downpipe on my rs3 8y. I have already bought an emulator to be able to remove the opf filter without having engine lights or problems of any kind. However, I'm looking for a solution to not turn on the engine light due to the 02 lambda probes. Does anyone have any solutions in mind? some emulator?
Thnaks

 

[Daggerit]

Hi, in a few days I will mount a 200 cell miltek downpipe on my rs3 8y. I have already bought an emulator to be able to remove the opf filter without having engine lights or problems of any kind. However, I'm looking for a solution to not turn on the engine light due to the 02 lambda probes. Does anyone have any solutions in mind? some emulator?
Thnaks

I believe there have been a few that have tried but always ended up with an engine light at some point. You can get mini CAT elements that bolt between the lambda sensor and it's mounting hole that fool the sensor but even these have proven to only last so long. That being said, if it lasted for 1000 miles before I had to clear one fault then I'd be happy enough with that I think.

I don't believe that there's an actual emulator for the CAT side of things but I could be wrong.

 

[LayZ_Pz]

Hi, in a few days I will mount a 200 cell miltek downpipe on my rs3 8y. I have already bought an emulator to be able to remove the opf filter without having engine lights or problems of any kind. However, I'm looking for a solution to not turn on the engine light due to the 02 lambda probes. Does anyone have any solutions in mind? some emulator?
Thnaks

Did you buy the seletron OPF simulator to achieve that?

 

[rs3_snowflake]

Did you buy the seletron OPF simulator to achieve that?

i already have the seletron emulator, but is only for opf sensor not o2 one

 

[LayZ_Pz]

i already have the seletron emulator, but is only for opf sensor not o2 one

Can you send a link to where you bought the Seletron emulator?

 

[8YARWY]

Can you send a link to where you bought the Seletron emulator?

RS3 (400hp - 294Kw - 2480ccm) - Seletron Performance

Choose EVC-SPORT, CHIPBOX, PEDALBOOSTER for your Audi, improve your car's power and engine performance. Seletron's products are entirely designed and manufactured in Italy, to ensure the quality that distinguishes the real value of Made in Italy.

seletron.com

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[Daggerit]

RS3 (400hp - 294Kw - 2480ccm) - Seletron Performance

Choose EVC-SPORT, CHIPBOX, PEDALBOOSTER for your Audi, improve your car's power and engine performance. Seletron's products are entirely designed and manufactured in Italy, to ensure the quality that distinguishes the real value of Made in Italy.

seletron.com

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I don't know if someone more adept at buying things from the EU than myself would be able to answer, but should the tax in Italy be removed from the goods before they're shipped since we're paying VAT over here? Or do we essentially get stung with two lots of tax?

 

[8YARWY]

I don't know if someone more adept at buying things from the EU than myself would be able to answer, but should the tax in Italy be removed from the goods before they're shipped since we're paying VAT over here? Or do we essentially get stung with two lots of tax?

Yup. No tax but pay at point of customs entry.

Was the same on my ASR group buy.


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[LayZ_Pz]

RS3 (400hp - 294Kw - 2480ccm) - Seletron Performance

Choose EVC-SPORT, CHIPBOX, PEDALBOOSTER for your Audi, improve your car's power and engine performance. Seletron's products are entirely designed and manufactured in Italy, to ensure the quality that distinguishes the real value of Made in Italy.

seletron.com

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Thank you mate, so is there even a remote chance to keep warranty with this? Do you have to remove full cat+opf (therefore drop subframe?) or am I wrong and there is an easier way?

 

[Daggerit]

Yup. No tax but pay at point of customs entry.

Was the same on my ASR group buy.


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That's what I was thinking. If you buy from Seletron, at the checkout the price stays at the post-Italian tax price so they don't seem to remove it before you purchase and maybe something to look out for in that case.

 

[Daggerit]

Thank you mate, so is there even a remote chance to keep warranty with this? Do you have to remove full cat+opf (therefore drop subframe?) or am I wrong and there is an easier way?

Someone in the ASR thread showed a picture of some OPF bypass pipes that had been installed, so you could go that way without taking out the cat(s). Failing that I think that it'll be a downpipe replacement and the installation time that goes along with it.

I also imagine that this would likely void your warranty since it's not something you can hide from Audi with either obvious bypass pipes or a different downpipe from OEM.

 

[8YARWY]

Thank you mate, so is there even a remote chance to keep warranty with this? Do you have to remove full cat+opf (therefore drop subframe?) or am I wrong and there is an easier way?

Lol not unless you go buy a full downpipe and butcher it…..

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[Daggerit]

Lol not unless you go buy a full downpipe and butcher it…..

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On that note, does anyone have access to the spares catalogue for the 8Y and 8V to see if the downpipes are the same part number? If so, I imagine there's a lot of cheap 8V downpipes going around.

 

[8YARWY]

On that note, does anyone have access to the spares catalogue for the 8Y and 8V to see if the downpipes are the same part number? If so, I imagine there's a lot of cheap 8V downpipes going around.

8Y 2023

8S0 253 005 A £4023 or

Same part number ending in X (remanufactured) £ 4049


8V

2020 8S0 253 005 £ 4023 or
same part number ending in X (remanufactured) £ 3273

Or……

There’s another part number for a 23/24 model.

Looks like it’s for countries with no OPF’s so it’s basically a Daza type down pipe

8S0 254 499F £ 3346

Or same part number with an X at the end (remanufactured) £1861


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[LayZ_Pz]

Lol not unless you go buy a full downpipe and butcher it…..

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I am not sure what I am looking at, I thought the CAT and OPF were on one pipe and if you want to get rid of the OPF you have to cut them out, am I wrong?
I want to stay within warranty as much as possible and therefore not cut anything so I am confused

 

[8YARWY]

I am not sure what I am looking at, I thought the CAT and OPF were on one pipe and if you want to get rid of the OPF you have to cut them out, am I wrong?
I want to stay within warranty as much as possible and therefore not cut anything so I am confused

The OPF’s were here and they’ve been cut out and replaced with straight thru pipes.

Here are the OPF’s from factory

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[Daggerit]

I am not sure what I am looking at, I thought the CAT and OPF were on one pipe and if you want to get rid of the OPF you have to cut them out, am I wrong?
I want to stay within warranty as much as possible and therefore not cut anything so I am confused

If you're trying to stay within warranty then I don't think that you should be touching them at all. Changing to a downpipe without them or cutting them out will certainly raise some eyebrows at the dealership. And to be honest, it causes other issues in terms of legality on the road and insurance because you've tampered with an emission control device.

That being said, it's the same thing as people running decat pipes and things so you pay your money and you take your chance if you're so inclined.

 

[8YARWY]

If you're trying to stay within warranty then I don't think that you should be touching them at all. Changing to a downpipe without them or cutting them out will certainly raise some eyebrows at the dealership. And to be honest, it causes other issues in terms of legality on the road and insurance because you've tampered with an emission control device.

That being said, it's the same thing as people running decat pipes and things so you pay your money and you take your chance if you're so inclined.

Most specialist insurance do tend to cover those mods, the problem now is the legal standpoint for removing a Particulate filter, I asked several insurance providers about it and they all came back from underwriters with a no not at all policy.
And if it was a serious accident they all now dig deeper into a cars setup, so if they get a whiff of something that voids a claim they will go full tilt on investigation works.


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[LayZ_Pz]

The OPF’s were here and they’ve been cut out and replaced with straight thru pipes.

Here are the OPF’s from factory

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Thank you! That makes much more sense, so to not cut anything and to be able to go back to stock you would need full downpipe replacement and you can deprecate the CAT+OPF stock tubing? And IIRC you need to drop the subframe to replace downpipe? I don't want to cut anything and I don't want to void warranty so something reversible if possible

 

[8YARWY]

Thank you! That makes much more sense, so to not cut anything and to be able to go back to stock you would need full downpipe replacement and you can deprecate the CAT+OPF stock tubing? And IIRC you need to drop the subframe to replace downpipe? I don't want to cut anything and I don't want to void warranty so something reversible if possible

Subframe dropped / prop shaft removed.

Propshaft needs kid gloves when handling to avoid disturbing centre section.


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[shahaf2911]

The OPF’s were here and they’ve been cut out and replaced with straight thru pipes.

Here are the OPF’s from factory

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Do you happen to have a video of just the OPF delete compared to stock ? I really want more sound but don’t won’t to go the downpipe route as is a no go in terms of warranty, OPF on the other hand is something I maybe be able to slide with my dealer in terms of warranty (as I know him and the 8V is basically the same engine without OPFs), I saw a lot of OPF removals but was unable to find one without a decat as well.. thanks in advance

 

[8YARWY]

Do you happen to have a video of just the OPF delete compared to stock ? I really want more sound but don’t won’t to go the downpipe route as is a no go in terms of warranty, OPF on the other hand is something I maybe be able to slide with my dealer in terms of warranty (as I know him and the 8V is basically the same engine without OPFs), I saw a lot of OPF removals but was unable to find one without a decat as well.. thanks in advance

I’d be wanting to hear it in real life before doing anything.
Very difficult to judge from a video.


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[shahaf2911]

I’d be wanting to hear it in real life before doing anything.
Very difficult to judge from a video.


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Ideally I agree but unfortunately there are only around 5-8 tops RS3 8Y in my country so it won’t happen, so a video will suffice haha but either way it will certainly make it louder it’s 2 huge filters I’d assume it would make a noticeable difference for 500€ and 2 pipes for the delete (I’d guess another 100-200€)

 

[shahaf2911]

Soooo no video of just an OPF/GPF delete ? (without a decat) searched YouTube hard but without success

 

[Daggerit]

Soooo no video of just an OPF/GPF delete ? (without a decat) searched YouTube hard but without success

Can't say I've seen one either to be honest.

 

[K44WMY]

Just reviving this thread. A sports catted downpipe lile the miltek one would be ok along with the seletron? As in i wont need to chop the opfs out? The miltek sports cat with opf delete would be just fine?

 

[Daggerit]

Just reviving this thread. A sports catted downpipe lile the miltek one would be ok along with the seletron? As in i wont need to chop the opfs out? The miltek sports cat with opf delete would be just fine?

I will give you what I believe is the right answer, but I haven’t tried it…

I think overall you’re right, the Miltek downpipe will be a direct bolt on and mean no chopping of the OPFs so that you can replace it when needed down the line for an MOT. The Seltron will simulate the OPFs so they don’t give you an error on the dash.

The issue I think pops up is an engine management light because of the cat, whether you run a sports cat or not. If I’m right, it’s because the likes of Miltek and other exhaust manufacturers place the cat further downstream in the exhaust compared to OEM and that means both your O2 sensors have to plug in before it (rather than one before and one after as OEM) because the one that should be downstream won’t reach. So basically the car thinks the car isn’t working.

I think Seletron give an OBD dongle to clear this and you just have to put up with it appearing, but I imagine if you could extend the correct O2 sensor wiring and position it just after a sports cat you’d be fine in that regard.

Hope that helps and is accurate for you!


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[8YARWY]

lol same old merry go round questions and answers……..
Why mess with the cat on a standard car that’s not mapped to accept this change, bonkers.


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[Daggerit]

lol same old merry go round questions and answers……..
Why mess with the cat on a standard car that’s not mapped to accept this change, bonkers.


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If I was going to do it, it would be purely for some more sound but I imagine I’ll just end up waiting until there’s some mapping available so I don’t have to rely on simulators and things…


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[K44WMY]

Thanks for the response. More than likely will get the bull x dp from holy grail.
You are correct in saying wait for tune etc, but some of us are impatient and waiting on a tune could be a while

 

[boosted_8]

Just reading through this thread as research to see how this works for Audi. From experience of running OPF deletes on BMW's, they run fine (no cel or odd driving behaviours) with emulators after a OPF reset using the appropriate software (ISTA for BMW). Primary cat deletes however are a different story without ECU tuning. Boost spikes, strong exhaust fuel smell and CELs are typical. You would need a Euro6 compliant downpipe with something like a HJS ECE grade sport cat to stand a chance of not trigging a cat efficacy error code.

 

[rs3_snowflake]

Just reading through this thread as research to see how this works for Audi. From experience of running OPF deletes on BMW's, they run fine (no cel or odd driving behaviours) with emulators after a OPF reset using the appropriate software (ISTA for BMW). Primary cat deletes however are a different story without ECU tuning. Boost spikes, strong exhaust fuel smell and CELs are typical. You would need a Euro6 compliant downpipe with something like a HJS ECE grade sport cat to stand a chance of not trigging a cat efficacy error code.

I know more than one person who has mounted the Seletron emulator with a 200 cell sports cat or with scat, both work and do not cause problems either in terms of lights or power delivery as you can see from the graph I attach (purple line), the engine works well and there are no strange disbursements. the smell of petrol is normal by removing the filters and you would have it even if you mapped the ecu (which I highly advise against)

 

[rs3_snowflake]

lol il solito giro vecchio di domande e risposte……..
Perché scherzare con il gatto su un'auto standard che non è mappata per accettare questo cambiamento, pazzo.


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simply because they work very well anyway. here in Italy mapping the control unit loses the warranty and is illegal for insurance companies. The mapped car is more difficult to resell and honestly still costs too much. For 3k euros my car without mapping it makes 500hp and goes great

 

[rs3_snowflake]

If I was going to do it, it would be purely for some more sound but I imagine I’ll just end up waiting until there’s some mapping available so I don’t have to rely on simulators and things…


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use the emulator, no worry, best option available now on the market...unless you need a stage 3 with 600hp, emulator is teh best option

 

[boosted_8]

I know more than one person who has mounted the Seletron emulator with a 200 cell sports cat or with scat, both work and do not cause problems either in terms of lights or power delivery as you can see from the graph I attach (purple line), the engine works well and there are no strange disbursements. the smell of petrol is normal by removing the filters and you would have it even if you mapped the ecu (which I highly advise against)

View attachment 273279

With a high quality sports cat I would not expect the need for emulation or a notable smell. On a B9 Audi S4 I ran a 200 Cell Miltek made HJS downpipe with no tune (just boost control piggyback box) or emulator for 3 years without a single issue.

 

[rs3_snowflake]

the emulator is necessary on new ones because it is used to emulate the pressures deriving from the opf filter (in the american market rs3 does not have it) and to alter the reading of the o2 probes, even with a quality cat the engine warning light and the car would enter limp mode. Without this the engine signals a carburetion problem because the opf sensor no longer communicates with the control unit. as regards the o2 probes, only one light comes on but it is yellow and would not cause any problems. the real problem is OPF, which is also the cause of the stock vacuum cleaner sound

 

[Daggerit]

With a high quality sports cat I would not expect the need for emulation or a notable smell. On a B9 Audi S4 I ran a 200 Cell Miltek made HJS downpipe with no tune (just boost control piggyback box) or emulator for 3 years without a single issue.

The B9 didn’t have OPFs though, which is what the emulator is for. Or at least my 2017 didn’t.

The other issue is that all aftermarket sport cat downpipes I’ve seen (maybe there are some not like this) position the cat further downstream than the OEM placement so the post cat O2 sensor actually ends up pre-cat and the car throws a wobbly eventually as it thinks the cat isn’t working. I think that’s the bigger issue than the OPFs at the moment.


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[boosted_8]

^ I'm not suggesting you can remove OPF without an emulator, It will absolutely go into limp mode. I am suggesting without ECU remap a catless downpipe is sub optimal and you would be better off using the OEM downpipe or Euro6 aftermarket downpipe instead.

 

[Daggerit]

^ I'm not suggesting you can remove OPF without an emulator, It will absolutely go into limp mode. I am suggesting without ECU remap a catless downpipe is sub optimal and you would be better off using the OEM downpipe or Euro6 aftermarket downpipe instead.

Gotcha. Since you’d said something about a cat and then emulator I was more just clarifying that the emulator isn’t for the cat, it’s for the OPFs.

I don’t know if it would be sub optimal or not to be honest, I’ve only ever seen more power made with a decat versus OEM but don’t know about that back to back with a good quality sports cat. I’d be very surprised if it made hardly any additional power though, as you say.

Plus, for me personally, I don’t like the raspy sound of a decatted car so would always prefer to go sports cat.


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[boosted_8]

I hate OPFs so much. Pulled two of them off my current car. If I can get a facelift RS3 this year its the first thing I will do right away!