[HawkStar]

Hi all! New round here and have just picked up a facelift A45s

Wondering if someone could advise on GPF back exhaust system? I wanted to purchase the Milltek system (SSXMZ153) whilst the sales were on but the supplier says it is only for 2019-2021 cars so cannot guarantee fitment.

Does anyone know a suitable GPF back system that would work on the facelift and one that wont throw any errors of any sort?

Many thanks

 

[K………]

Is it possible to fit a akra downpipe without going stage 2?

 

[Spuddy]

Afternoon,

Does anyone know if any companies sell a rear muffler delete on its own rather than an entire exhaust? I still have some warranty left and Mercedes told me the best I could do was swap out the back box if I wanted to retain the warranty.

The car is just gutless when it comes to sound. I have already modded the valve to be open all the time but it hardly made a difference.

Any advice is welcome

 

[Forrester]

Thanks veeeight that’s put my mind at rest. I’ll update the continuous running fan thread (and this one) after the dealer visit next week.

So far (two months ownership) this 2022 car has proven to be a challenge. I’ve had the full house of “they all do that” problems from rattling seatbelts (against the side panel), a recall for something to be replaced underneath at the rear end (unspecified in the paperwork), a carboned up exhaust flap at the rear and now these two coolant related issues. I’m getting my money out of the remaining Mercedes warranty on the vehicle.

In comparison my previous A45 (2016) bought from new had no issues and sounded much more like an AMG than this facelift “S” with more bhp.

it’s off to cobrasport tomorrow as a test vehicle for a venom system. To see what differences are underneath the A45 and GLA45. Hopefully it will come back sounding more AMG like. Although I’m sticking with keeping the down pipe while it’s under warranty, and they’ve warned me most of the crackle won’t be unleashed until this is replaced and it’s remapped at a later date. Admiral were a reasonable £13 extra for exhaust mods for the remaining 6 months of the policy.

Sorry for the ramble. It’s good to be in contact with people who know these vehicles and offer help. The local main dealer hasn’t exactly been supportive since my return to Mercedes ownership. Every problem I’ve had with the car is a known one and yet I’ve had to force their hand and guide the diagnosis under threat of £200 if no fault found.

From what you say about your car being a test vehicle I'm guessing its done some hard miles in the two months. What's your mileage overall.

 

[Theo]

In comparison my previous A45 (2016) bought from new had no issues and sounded much more like an AMG than this facelift “S” with more bhp.

it’s off to cobrasport tomorrow as a test vehicle for a venom system. To see what differences are underneath the A45 and GLA45. Hopefully it will come back sounding more AMG like. Although I’m sticking with keeping the down pipe while it’s under warranty, and they’ve warned me most of the crackle won’t be unleashed until this is replaced and it’s remapped at a later date. Admiral were a reasonable £13 extra for exhaust mods for the remaining 6 months of the policy.

Everything else has already been insightfully answered so, RE our engine's sound, it's all to do with Euro 6+. Have you listened to the new RS3? Sounds better than our 4cyl for sure, but still far from what it used to. They're all muted nowadays. But it's nothing to do with the engine, the M139 actually sounds terrific, in fact sounds a lot bigger than a 4cyl, all you have to do is remove the downpipe together with the GPF that's responsible for the lack of sound and install a sports cat, a 200cell will be fine. Going full exhaust (replacing the catback too) will deepen the sound a bit further, if you're into that. However note that a catback alone will only deepen the stock sound, so definitely get a downpipe and get rid of the GPF if you want the real thing. Then you're going to see how beautiful, deep, near V6 it sounds, if you haven't already watched videos of the A45s fitted with exhaust systems such as Armytrix and Capristo. For real, you should watch a video if you haven't. It's the one and only reason I intend to tune mine, not for the hp gain. I understand you want to wait while you're under warranty, but at least know that your car will sound amazing when you're ready!

 

[.Griff.]

So it's driving season again and last weekend I spent time in the company of 60 other cars on our first driving tour of the year. There was everything from a 1970s Jensen through to new Porsche GT3s and everything in between.

Watching the videos back one thing stood out - just how quiet my A45s is. My old W176 was much less refined but it had much better audio aesthetics.

I may or may not keep the car at the end of the term so what is the best way of extracting more sound out of it while at the same time being able to return it to factory standard if needed? I'm under the impression that if I want a different rear box or even cat-back this involves cutting the factory exhaust. Is that correct?

 

[Theo]

As I have previously mentioned, our engines themselves actually sound amazing, in my opinion one of the best sounding 4cyl, but the GPF robs all these beautiful exhaust tones. With a full turboback exhaust which removes the GPF, it sounds so good it actually makes near V6 flybys, but I assume you have already watched videos of the A45s fitted with Armytrix or Capristo full turboback exhausts so you know what I'm talking about. The reason I'm telling you this, is that this is the real deal, the only way for this car to truly sound hot AF. But, it comes with the risk of warranty void. If it's something you're not interested in, your only other option is what you said, catback or just the rear box, but it will never sound anything like the real thing, it's literally night and day. What you're going to hear is the factory sound amplified, nothing more. A full turboback with GPF-delete, not only does it sound a lot louder, it makes a completely different, very distinct, near V6 tone.

If you haven't watched any videos, here is an example at 4:44. Tell me it doesn't make nearly the same kind of growl as a Golf R32 VR6.

If warranty isn't an issue and your only concern is being able to return it back to factory standard, you can do that with a full turboback, just keep your stock exhaust. I always did that in all my tuned and modified cars, although I never needed it.

 

[.Griff.]

Hi Theo,

Thanks for the comprehensive response. I had no doubt there's a great sounding 4pot in there somewhere, but as you said the GPF ruins it.

My warranty runs for another 15 months so I need to factor that in. If it was out of warranty, and I had the cash at my disposal then I'd have a turbo back system tomorrow.

I was just curious if I was missing a trick and if there was a warranty friendly way of extracting some more emotion out of it for now.

 

[Forrester]

Hi Theo,

Thanks for the comprehensive response. I had no doubt there's a great sounding 4pot in there somewhere, but as you said the GPF ruins it.

My warranty runs for another 15 months so I need to factor that in. If it was out of warranty, and I had the cash at my disposal then I'd have a turbo back system tomorrow.

I was just curious if I was missing a trick and if there was a warranty friendly way of extracting some more emotion out of it for now.

We were under the impression in the early days that you could at least get rid of the piped sound using the dealer menu but that turned out not to work and I think its Theo's way or putting up with the way it is externally.

 

[Theo]

Hi Theo,

Thanks for the comprehensive response. I had no doubt there's a great sounding 4pot in there somewhere, but as you said the GPF ruins it.

My warranty runs for another 15 months so I need to factor that in. If it was out of warranty, and I had the cash at my disposal then I'd have a turbo back system tomorrow.

I was just curious if I was missing a trick and if there was a warranty friendly way of extracting some more emotion out of it for now.

Sure. Well look, you could get a catback for now, but do check with your dealer and make sure it's not enough to void your warranty. Normally, it shouldn't, because from technical perspective, you're not actually changing anything. You still have the GPF, O2 sensors are still there, basically the ECU still thinks nothing has changed. Anyways check with your dealer and if you're clear, get a catback, enjoy a more pronounced tone and wait until warranty expires to get the downpipe and truly unlock the symphony behind it. You're not going to need to cut your aftermarket catback. It's a win-win.

Wife and I are in the middle of completing our big turbo Cupra project, currently doing an engine build to be able to run high boost, then need to break it in and if everything is fine for a month after the final tune, I'll put all my energy into the A45s. I'm just not fond of working on both at the same time, not to mention the $$$.

 

[Sjd_666]

I went to see Paul @ https://www.exhaustmods.co.uk/
Had the internals of the oem exhaust modified. Sounds a lot better. Had it done while still under warranty

 

[Sixman]

No GPF, individual mode with higher revs and shift points, AMG performance sound...my a45s is louder, better sounding than a W204 c63 I had way back.

 

[Spuddy]

Afternoon,

Does anyone know if it is possible to buy a factory Catalytic converter from the non OPF model and if it would directly fit the UK model?

I know it would cost more than aftermarket but I think it's an easy way to get rid of the OPF without a tune.

Would also need this: XPF Emulator | Seletron

 

[Forrester]

Afternoon,

Does anyone know if it is possible to buy a factory Catalytic converter from the non OPF model and if it would directly fit the UK model?

I know it would cost more than aftermarket but I think it's an easy way to get rid of the OPF without a tune.

Would also need this: XPF Emulator | Seletron

Hopefully @Theo sees your question. He should be able to answer it.

 

[Theo]

Afternoon,

Does anyone know if it is possible to buy a factory Catalytic converter from the non OPF model and if it would directly fit the UK model?

I know it would cost more than aftermarket but I think it's an easy way to get rid of the OPF without a tune.

Would also need this: XPF Emulator | Seletron

Hopefully @Theo sees your question. He should be able to answer it.

Nah, wish I could help. I don't have data on diameters and whatnot, but worst case an adaptor should be able to fix it. Software might be a problem though, as I'm pretty sure it's different between the two versions. Again, I have no actual data, but think about it, how does it account for the lack of GPF otherwise? Fitting any aftermarket GPF-less cat it's going to throw a CEL. How's that any different from fitting the stock GPF-less cat, it's still without GPF. So that said, you would need a tune, or some changes in the software anyway, however you wanna call it, XPF, Seletron, whatever. So next question would be about the warranty and maybe MOT (?) don't know how strict those are in the UK.

So, yeah, not sure if it's doable or not, just asking the same questions I would ask myself if I were in your shoes. I plan to get rid of mine too, but with an aftermarket TBE, GPF-less cat and a custom tune. Warranty is long expired anyway, and emissions/inspection would be the least of my concerns if it came to that, it's not a straight pipe after all.

Sorry I couldn't be of more help.

 

[Jevexy]

Hello everyone.

I wondered about improving the sound of the standard exhaust system (there is no warranty on the car and environmental standards are not observed in the country)

I have a 2021 A45 W177, and after studying the easiest way to get a good exhaust is to replace the catalytic converter with a downpipe, or a sports catalytic converter 200/300 goal. As far as I understand, by installing a catback, the sound will still be muffled due to the limitations of the catalytic converter, but you can install a titanium catback (the price is huge)

But the only problem is that after installing a downpipe or sports catalytic converter, you can't leave the car in stock and you need to flash it, but I did not plan to increase the power.

Tuning studios offer the option of disabling the second lambda and polling the catalytic converter, and they assure that all systems work correctly without increasing the power, but I find it hard to believe.

I would like to ask you what your thoughts are on this matter, maybe there are simpler solutions, so as not to get into the car firmware?

Thanks in advance!

 

[Theo]

Hello everyone.

I wondered about improving the sound of the standard exhaust system (there is no warranty on the car and environmental standards are not observed in the country)

I have a 2021 A45 W177, and after studying the easiest way to get a good exhaust is to replace the catalytic converter with a downpipe, or a sports catalytic converter 200/300 goal. As far as I understand, by installing a catback, the sound will still be muffled due to the limitations of the catalytic converter, but you can install a titanium catback (the price is huge)

But the only problem is that after installing a downpipe or sports catalytic converter, you can't leave the car in stock and you need to flash it, but I did not plan to increase the power.

Tuning studios offer the option of disabling the second lambda and polling the catalytic converter, and they assure that all systems work correctly without increasing the power, but I find it hard to believe.

I would like to ask you what your thoughts are on this matter, maybe there are simpler solutions, so as not to get into the car firmware?

Thanks in advance!

Yes, you absolutely can code the ECU to not throw a CEL without increasing power, if that's what you want. And yes, unfortunately the M139 needs a downpipe (getting rid of the GPF) if you want to unlock the full sound and get that wonderful, distinct growl. As for cat, a 200cell is the perfect, fully street-legal choice. Catbacks are cheaper and safer solutions (safer in the sense that they won't void your warranty) compared to downpipes, but sound-wise they don't come remotely close. That being said, for best results you want both, so what you want is a full turboback exhaust (aka TBE) preferably non-resonated. If it's too much, get it resonated. The car will still be environmentally friendly btw, it just won't be stupid Euro 6.

Edit: Oh wait, you shouldn't have a GPF. It should sound a little better even stock. Well either way, like I said for best results you need a TBE.

 

[Jevexy]

Yes, you absolutely can code the ECU to not throw a CEL without increasing power, if that's what you want. And yes, unfortunately the M139 needs a downpipe (getting rid of the GPF) if you want to unlock the full sound and get that wonderful, distinct growl. As for cat, a 200cell is the perfect, fully street-legal choice. Catbacks are cheaper and safer solutions (safer in the sense that they won't void your warranty) compared to downpipes, but sound-wise they don't come remotely close. That being said, for best results you want both, so what you want is a full turboback exhaust (aka TBE) preferably non-resonated. If it's too much, get it resonated. The car will still be environmentally friendly btw, it just won't be stupid Euro 6.

Edit: Oh wait, you shouldn't have a GPF. It should sound a little better even stock. Well either way, like I said for best results you need a TBE.

Thanks dear

 

[Jevexy]

I'm alredy ordered Capristo, i hope its good choise

 

[Jevexy]

Yes, you absolutely can code the ECU to not throw a CEL without increasing power, if that's what you want. And yes, unfortunately the M139 needs a downpipe (getting rid of the GPF) if you want to unlock the full sound and get that wonderful, distinct growl. As for cat, a 200cell is the perfect, fully street-legal choice. Catbacks are cheaper and safer solutions (safer in the sense that they won't void your warranty) compared to downpipes, but sound-wise they don't come remotely close. That being said, for best results you want both, so what you want is a full turboback exhaust (aka TBE) preferably non-resonated. If it's too much, get it resonated. The car will still be environmentally friendly btw, it just won't be stupid Euro 6.

Edit: Oh wait, you shouldn't have a GPF. It should sound a little better even stock. Well either way, like I said for best results you need a TBE.

Please tell me, have you remap your car?

Did you just turn off the catalytic converter or increase the power?

If you increased the power, by how much? Since in my city they offer tuning solutions for 500+ horsepower, which seems to me catastrophically high for this engine.