Custom Exhaust Fabrication 4200 CC

[Mr S]

On a side note, is it possible to cut open the US spec headers, replace the cats with decent sports ones, and reweld it call back together? Not sure if this would be seen as a bodge, or less hassle and cheaper than replacing the headers, and secondary pipes.

 

[lifes2short]

Wait, you have a 6R4!?? Pictures please!!

this is she, bit of a beast

 

[TimR]

On a side note, is it possible to cut open the US spec headers, replace the cats with decent sports ones, and reweld it call back together? Not sure if this would be seen as a bodge, or less hassle and cheaper than replacing the headers, and secondary pipes.

I have heard of someone having done this, or something similar....
Eurospec cars remove primary cats and replace secondaries with a 200 cell cats, one on each side, and still get through emissions ok.
Bucket chemistry would suggest that the primary cats could be replaced with straight through header modification, and still offer more emissions control than this...Whether they test a US spec car to a different standard I very much doubt as there is obvious "parts bin" anomaly with GS's being made with euro psec exhaust systems..?
That said, the o2 sensors would still need to be present. Im no expert but I cant see how this is different from the Euro spec cars..only the position. What matters is their relative values in terms of function ( they work in pairs )
Would be interesting to hear from someone who has done this. Im sure the throttle would feel alot better for it, and it would seem a simpler approach than a reversion to the earlier system, as they arent bolt-on, bolt-off compatible ....
Any of the cat delete systems offered are all made for the euro spec cars ( 4 bolt stud pattern)- the ones Ive been able to find anyway; and typically retail around £1600, so its not a crazy stupid idea imo !?

 

[Zep]

On a side note, is it possible to cut open the US spec headers, replace the cats with decent sports ones, and reweld it call back together? Not sure if this would be seen as a bodge, or less hassle and cheaper than replacing the headers, and secondary pipes.

I doubt it, you would effectively have to cut the van in half to get the new cat into the casing and then you would need to be sure that it was properly supported.

 

[Carrera]

bought 2 stainless boxes off them and a range of stainless mandrel bends to build the system on my 6R4, found the quality of the boxes and welds very good and been on motor for a couple of years and still all good

View attachment 56697

 

[Carrera]

Thanks all my understanding has come on leaps and bounds! My 2003 car has a Euro spec system fitted. After the manifold in the first part of the exhaust is a primary cat followed by the squashed section and the the secondary cat (all one piece). Having spoken to Marios at Autoshield he is suggesting removing the first cat but leaving the original second cat is place. Then swap the resonator for a X- pipe and fitting a straight through pipes on the end eliminating the back boxes. Has anyone tried this combination and would it be silly loud? Also is there a benefit in performance in removing the primary cats but leaving the secondary one is place?

 

[Mike X]

Marios certainly knows his stuff

 

[Navcorr]

I have heard of someone having done this, or something similar....

Did the erstwhile Mr C. Waterman, of distant shores, not gut primary cats some time ago?
I'm sure there's a vid on YT.

 

[giorgio01]

I went with a Marios X pipe and Jaren modified back boxes , the sound is gorgeous , no drone at all , Jason does a fantastic job , as mentioned , of polishing them and fettling them to look as good if not better than new .View attachment 56708

Hi, where I can buy that X pipe please?

 

[giorgio01]

Here’s what I went for, one pair of cats removed as well as squashed pipe.
Plus centre resonator replaced, back boxes standard.
Sounds great

Hi,
Can you please tell me where I can get that center resonator replacement pipe? Thanks

 

[Gazcw]

Hi,
Can you please tell me where I can get that center resonator replacement pipe? Thanks

Larini = nice and shiny version or Marios at http://www.autoshieldmaserati.co.uk/. He is on here too. Pm him.

 

[Gp79]

Hi,
Can you please tell me where I can get that center resonator replacement pipe? Thanks

Hi mate,

Mine is a Bertocchi / Miracolare I picked up used a few years ago, originally made in Japan.

Try: tezta.com/bertocchi

 

[Gp79]

Hi,
Can you please tell me where I can get that center resonator replacement pipe? Thanks

Different central resonator but you get the idea

 

[Simon1963]

My 4200 had an exhaust system made by MIJ on it when I bought it, quality is not great, and I certainly wouldn't go anywhere near them.

I had a cat back system made by mij a few years ago on a 5series BMW and the quality was rubbish. Ended up in France tying it up with wire after it had been on about 3 months.

 

[Corranga]

Thanks all my understanding has come on leaps and bounds! My 2003 car has a Euro spec system fitted. After the manifold in the first part of the exhaust is a primary cat followed by the squashed section and the the secondary cat (all one piece). Having spoken to Marios at Autoshield he is suggesting removing the first cat but leaving the original second cat is place. Then swap the resonator for a X-pipe and fitting a straight through pipes on the end eliminating the back boxes. Has anyone tried this combination and would it be silly loud? Also is there a benefit in performance in removing the primary cats but leaving the secondary one is place?

I'm going through the same learning experience right now...

Looking at the parts diagram via Euro Spares: https://www.eurospares.co.uk/parts/maserati/4200-coupe/exhausts/exhaust-system-20129
If you remove the front cat, but retain the rear one, does it cause an issue with the sensors?
I gather the 2nd set of sensors, located between the cars, is a thermocouple, which I presume just does exhaust gas temperature?

Some pictures incase I'm being an idiot!

Standard set up:



The Larini pipe retains the original position for the thermocouple to behind the cat - despite only having 1 cat, and it being in the rear location:

 

[jasst]

No, there are 4 lambdas , and 2 thermocouples, there are 2 lambdas in front of the first cat, and 2 after the first cat. If you remove the primary cat, you need to move the 2nd lambdas to after the secondary cat, (unlike what someone did to mine, I know who you are!) in your second picture of the larine, where you have marked thermocouple in purple is in fact the location of the second lamdas, and if you have your existing system modified you need to make sure it is done like this.

 

[mjheathcote]

I think the thermocouples were only fitted to early 4200.
Stand to be corrected though!

 

[Corranga]

Ok, so the post above that mentioned removing the front cats then means that front and rear lambdas are then not deprecated by a cat which surely causes issues?

 

[Zep]

I think the thermocouples were only fitted to early 4200.
Stand to be corrected though!

Indeed!

 

[Zep]

Ok, so the post above that mentioned removing the front cats then means that front and rear lambdas are then not deprecated by a cat which surely causes issues?

Exactly. The rear lambda needs to be moved to behind the secondary cat. I have been told that if it is reset the CEL shouldn’t reappear but that seems like a cludge to me.