RS3 8Y OPF and Cat Delete (2024)

Daggerit said:

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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the cat positioned lower is much better, it prevents there being an obstruction for the gases and in fact the turbine is cooled much better. The seletron emulator also manages to create fake signals for the 02 probes to avoid problems. the emulator is physically the same, you don't have to buy 2 but only one which works for both opf and o2 probes

rs3_snowflake said:

the cat positioned lower is much better, it prevents there being an obstruction for the gases and in fact the turbine is cooled much better. The seletron emulator also manages to create fake signals for the 02 probes to avoid problems. the emulator is physically the same, you don't have to buy 2 but only one which works for both opf and o2 probes

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I can understand why it’s done, it just doesn’t help for the O2 signals is all.

Good to know they have an emulator that does both though, that’s really helpful!

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boosted_8 said:

^ 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.

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please don't give false information. having catless with emulator on rs3 8y does not negatively affect engine performance. as I have attached the graph, there are no gaps in power and the engine, after careful analysis, has no problems. The new control units are able to guarantee optimal carburetion even with a modified dp. I say this because I have tried it and here in Italy there are hundreds of RS3s circulating using this emulator without ever reporting problems of any kind. At the moment mapping the control unit is not recommended both due to the price and the developments which are still in an embryonic state.
I want the information to be as clear and true as possible, I've seen too many cars blown up due to poorly done mapping.

This one in the video for example is a friend of mine also with catless and original RS terminal. Use the same emulator as me

View: https://drive.google.com/file/d/1L8OWgWhdnreVj1QD6na51pjMXgwzaoJf/view?usp=sharing

Daggerit said:

I can understand why it’s done, it just doesn’t help for the O2 signals is all.

Good to know they have an emulator that does both though, that’s really helpful!

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I confirm that it doesn't help but honestly I don't see it as a problem...in fact it only brings benefits. Since there are emulators that do this, it makes no difference whether the probes are mounted correctly or not. I personally have dp without opf and I also have the milltek terminal. The sound is perfect and the car has no problems whatsoever after 10k km
At the moment I don't consider mapping a valid choice unless you want to have a stage 3 but in that case the exhaust would be the least of your problems

View: https://drive.google.com/file/d/1JwdzhX7oczTbIKw1GJYg8QGcyBY5VoV9/view?usp=sharing

boosted_8 said:

@rs3_snowflake please don't misunderstand - My opinion and experience of running catless downpipes has no relation to the effectiveness of safety of your product. I'm certain there are happy customers doing such without issue. I just don't like the sound, smell or part throttle boost character personally.

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First of all I would like to clarify that this is not my product, I purchased it but I don't produce it and I don't get paid to advertise it, I simply like it very much and recommend it.

Having said that, I really appreciate your experience and your opinion but I wouldn't want the wrong message to get across. What I write is the result of experience with the emulator in question and with the use of it, it is not based on past experiences or with other cars. I haven't found the problems you point out using this modification, the sound is the classic 5-cylinder one, the accelerator has the right grip (obviously there is turbo lag) but this guarantees that the car has excellent grip and that it doesn't it's just a drift game; the smell is normal, with or without the map by changing the dp you have it, there are cars that do it more and cars that do it less but it is inevitable by physically changing a component that usually filters the exhaust gases.

I would like this to be clear since I saw that the topic of the post was moving towards discrediting this type of solution. I would like to underline that by using this type of emulator you will not lose the warranty, I have personally been to Audi in do maintenance on the car and my warranty is still there. In the event of serious damage to the engine, simply disconnect it, fit the original DP and there are no changes to the car's control unit and the warranty remains active; which does NOT happen in the case of ECU mapping.

boosted_8 said:

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!

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Its surprising the RS3 doesn't make less power with OPF compared to the 8V.