AMG GT-R issue - help required

[Steveml63]

Hi,
I believe that cats on modified cars will get damaged by a combination of extra heat and the concussion effect of the bangs & pops of unburnt fuel exploding in them.
The working parts of a catalytic converter are a platinum (and other rare metals) coated ceramic honeycomb - so the explosions will weaken this structure and cause cracks and sharp edges - those edges can then get burnt.
It’s a bit like trying to catch fire to a thick book - it only works if you start tearing pages out of it and causing lots of edges to catch fire.
Cheers
Steve

 

[Bobby Dazzler]

Sound like it is likely not the car currently on Autotrader nor @shindy car. That accounts for 50% of UK cars in Solarbeam.

Lets see your AMGs | AMG Lounge

rare colour amg gtr owned since june 2022 love it!!!

forums.mbclub.co.uk

amg gtr | AMG Lounge

 

[Simon737]

So….a bit more info re the car. Turns out it had a misfire fault back in January which sounds like its ultimately led to the failure of the cats over time. The engine as far as MB can see hasn’t been remapped - what I’m not sure of at this stage is whether the misfire was fixed or not - if it was it was obv done too late and the damage had been done - but MB can see that it wasn’t repaired by them. Parts on back order for 6 months. At this point I’ve had enough - demanding a full refund and to get out of this thing asap. I’ll go back to my local MB dealer who have been outstanding helping me along the process and hopefully they can source me another GTR and I can enjoy the car for what it really is an about.

 

[Bobby Dazzler]

So….a bit more info re the car. Turns out it had a misfire fault back in January which sounds like its ultimately led to the failure of the cats over time. The engine as far as MB can see hasn’t been remapped - what I’m not sure of at this stage is whether the misfire was fixed or not - if it was it was obv done too late and the damage had been done - but MB can see that it wasn’t repaired by them. Parts on back order for 6 months. At this point I’ve had enough - demanding a full refund and to get out of this thing asap. I’ll go back to my local MB dealer who have been outstanding helping me along the process and hopefully they can source me another GTR and I can enjoy the car for what it really is an about.

If you’re going to reject then it’s easier to do it sooner rather than later as long as you’ve given the seller an opportunity to make good first.

Good to hear that you’ve received good service from the main dealer, many are quick to publically criticise but few are quick to give credit where it’s due.

Good luck with the search for the next. It will be worth it, they’re great cars, and one of the very best.

 

[Simon737]

Melting catalytic converters must take some doing , they often operate normally at around 700 degrees Celsius , they must have been at double that to melt (If stainless) , I'm surprised the car did not burst into flames if thats the case.

OP says there are only 4 of this colour in the UK and yet no one seems to 'know' the car .

Apropos of nothing here is a damaged cat that I replaced on my Toyota Yaris run around . To this day I have no Idea how it happened EML light came on because input and output temperatures were out of whack.

View attachment 146011



PS , Nice car , should be out and about being enjoyed , not parked up , shame really (The GT-R , not the Yaris )

Yeah you’re not wrong I’ve been told in order to get the cats to melt on this thing, they’ve been up at 1000c - so pretty much glowing underneath the car!!! Thank god I didn’t drive it over a dry grass field!

 

[Simon737]

Not really looked at after market stuff re the cats/downpipes - does anyone have any experience or can point me in the right direction. With a potential 6 month wait for OEM parts there must be something that’s easier to get hold of….I know I ranted yesterday re getting rid of the car but I do really love it and want to find a solution (I’ll take the dealer to court over it anyway) and came across this for 1/3 the price Merc want to charge….no experience with this stuff at all but guessing gaskets/seals required too?

Mercedes AMG GT GT S GT R downpipes

AMG GT GTS downpipes sport exhaust Brondex

brondexshop.com

 

[BTB 500]

If you go the non-OE route I'd have thought any decent exhaust shop should be able to sort you out. Hardly the same thing but I had 200 cell sports cats fitted to my SL500 by a local Longlife franchise. The car was subsequently MOT'd by a main dealer every year without any adverse comment at all (in fact one of the staff remarked on how good it sounded ).

No personal experience of them but places like MSL (already mentioned in this thread) seem to have a pretty good reputation here ... not too far from you either:

MSL Performance

MSL Performance

mslperformance.co.uk

 

[SpikyMikey]

Another option maybe to find a Powerflow or Longlife dealership near you to see if they can custom fabricate what you need
Edit beaten to the gun by BTB 500 !

 

[Steve84N]

Most aftermarket sports cats are 200 cell versus the more typical 400 cell OEM. They also tend to be metallic rather than ceramic. This means they flow better and are more resistant to higher temperatures.

You would need to declare the exhaust downpipes as a modification for insurance. Strictly speaking it's illegal but in practice you'll probably pass an MOT as they can be hidden by the undertrays and it has low enough emissions. Best to leave the rest of the exhaust standard because a sports cat also makes it louder.

 

[Simon737]

What would you do:-

Court action and wait….
Pay MB £7.8k and keep it stock wait is up to 6 months for parts…..
Aftermarket and ECU stage 2 done in 3 weeks….
Get rid….

 

[Bobby Dazzler]

If you feel like taking a brave pill then you could go for catless headers.

Look up @supercar_olly on Instagram, he’s just fitted some @br_motorsport on his GT (not a GT R) and he’s besotted with them.

 

[Simon737]

If you feel like taking a brave pill then you could go for catless headers.

Look up @supercar_olly on Instagram, he’s just fitted some @br_motorsport on his GT (not a GT R) and he’s besotted with them.

Would love to but I don’t (at this stage) have the stock cats to put back on for MOT…. decat would be a fail

 

[Jobsworth]

What would you do:-

Court action and wait….
Pay MB £7.8k and keep it stock wait is up to 6 months for parts…..
Aftermarket and ECU stage 2 done in 3 weeks….
Get rid….

It entirely depends on what you are looking for. If you have had it with the car and just want out then it can probably be done pretty easy.
If you love it and are prepared to get it sorted then it’s just a choice of two. If you want the investment potential it has to be an OEM fix. Anything less is modified, and it tends not to hold its value quite as well.
If it’s ultimate performance then decats and remap and you’ll probably blow your socks off. These cars are amazing tuned. Tbh they are pretty amazing stock, but tuned is another level.
If it’s really killing you I’ll take it off your hands for a depressingly low bid

 

[Bobby Dazzler]

Would love to but I don’t (at this stage) have the stock cats to put back on for MOT…. decat would be a fail

With replaced catless down pipes refitting the cats isn’t an option. It seems cars do pass without the cars. The MOT tester could fail a car if they believe the cats have been removed but it seems that cars still pass.

 

[Simon737]

It’s a head and heart scenario. Head says, stock, court, fight it go back to what I had. Heart says, downpipe, sport cat, stage 2 +700hp and bloody enjoy the thing!

 

[badgx]

You have a beautiful car, if it were mine, I would have completed a sports CAT 200 cell mod by now and during winter time when the temperatures are colder, take it down to msl for a stage2 map and get them to do a once over check.

I don't think i would risk putting a new stock system at the moment, without having a check and risk it getting melted again. Can always purchase oem stock system anytime later in the future, it's totally reversible mod.

You'll also enjoy the exhaust note

Here mine, it's just a saloon car but I think it sounds pretty good.

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[Stevie1982]

It’s a head and heart scenario. Head says, stock, court, fight it go back to what I had. Heart says, downpipe, sport cat, stage 2 +700hp and bloody enjoy the thing!

Honestly I know I'll probably get shot to bits for this, I feel you will struggle to get the dealer, simply because the car has run fine (albeit silly high temps) and unbeknown to you for 4 months and has covered X miles in this time. The dealer was not to know and as long as can prove it was serviced accordingly, mot'd, pdi completed then I struggle to see you winning in a small claims. Also have you been in communication with the supplying dealer since the issue and afforded them the chance to fix it?

The time, effort, stress and money it will take as I believe even as a the claimant you have to outlay the money on the case on the hope you win and get it back, if you don't win you'll be out the repair work and the court fees.

If you love the car, fix, tune it and move on, lifes to short.

 

[Simon737]

Honestly I know I'll probably get shot to bits for this, I feel you will struggle to get the dealer, simply because the car has run fine (albeit silly high temps) and unbeknown to you for 4 months and has covered X miles in this time. The dealer was not to know and as long as can prove it was serviced accordingly, mot'd, pdi completed then I struggle to see you winning in a small claims. Also have you been in communication with the supplying dealer since the issue and afforded them the chance to fix it?

The time, effort, stress and money it will take as I believe even as a the claimant you have to outlay the money on the case on the hope you win and get it back, if you don't win you'll be out the repair work and the court fees.

If you love the car, fix, tune it and move on, lifes to short.

I hear you and thanks for your advice - I’ve been in touch with them plenty of times and given them an opportunity to put it right but they don’t reply or return my calls.

As you say perhaps it’s time to move on.

Questions re the sports cat’s - I have a servicing pack on the car via MB (MOT’s incl) - will they still service the car after these have been fitted and the ECU stage 2 remap??

 

[Stevie1982]

I hear you and thanks for your advice - I’ve been in touch with them plenty of times and given them an opportunity to put it right but they don’t reply or return my calls.

As you say perhaps it’s time to move on.

Questions re the sports cat’s - I have a servicing pack on the car via MB (MOT’s incl) - will they still service the car after these have been fitted and the ECU stage 2 remap??

Try sending a legal letter, there's an owner who has had a engine failure on here. I'm sure he would be able to put you in contact with the solicitor he is using. See if that provokes a reaction. Offer a solution that you are happy with if not threaten small claims court. Theyay come back with an offer that you are willing to work with.

No one wants to drop 4 to 5k of thier own money yet in the long scheme of things it's not a lot of money. Pay it, fix it, move on and enjoy life.

can't see why it would impact the service pack. Plus why would you need to tell them.

 

[AMGeed]

Questions re the sports cat’s - I have a servicing pack on the car via MB (MOT’s incl) - will they still service the car after these have been fitted and the ECU stage 2 remap??

The main dealer will still service your car if it has a remap and sports cats. Just ensure the service manager notes on the job sheet before the service not to apply any update the engine ECU or TCU if that has been updated by the tuner.
That's what I told MB Poole and it was no problem. I'm sure main dealers see remapped cars in for a service quite often.