4200 Cats

[Yeti]

Been trawling the various posts regarding cats. Have had Red Shed down at Shiltech for a thorough service and to sort some minor problems. Seems my front cats are dying so was wondering what solutions people have come up with to sort this? Don't fancy paying for original Maserati cats, Askew can't get any and Larini seem stupid expensive. Did think about having the cats removed and straight pipes put on but it seems this will leave the engine light on. Would rather like to improve the noise while rep[lacing the cats. Idea's?

 

[safrane]

Just get 200 cel units welded in there instead of the OEMs

 

[FIFTY]

I am deleting the primary and just having a 200 cell secondary on each side. Waiting for the exhaust flanges to get cut so I can get it done already but the guy at the laser cutters is taking his sweet time.

You will also need lambda bosses and the cats which your exhaust guy may be able to supply. With the lambdas plugged in to the new sections you will not get a CEL

 

[Yeti]

I am deleting the primary and just having a 200 cell secondary on each side. Waiting for the exhaust flanges to get cut so I can get it done already but the guy at the laser cutters is taking his sweet time.

You will also need lambda bosses and the cats which your exhaust guy may be able to supply. With the lambdas plugged in to the new sections you will not get a CEL

Any suggestions as to who could do this in the East Midlands?

 

[FIFTY]

Check the yellow pages for a laser cutters, Spartacus has done the drawings for the flanges, you can contact him for this.

You need to find an exhaust fabricator, I am going to use Berkshire garage in Newbury which is a bit out for you. MIJ in walsall have some experience with maserati but I have read mixed reviews.

Also not sure if you are aware but the cats section of the exhaust swoops under the steering rack, the designers "squished" this section of pipe to restrict the performance of the car. Larini have their twin pipe solution but many have gone "fully round" on their custom cats and apparently have had no problems with ground clerence. At any rate there is a decent boost to the performance and throttle response for only £550

 

[mjheathcote]

the designers "squished" this section of pipe to restrict the performance of the car

...they actually increased the diameter of the exhaust at that point before squashing it, so the cross sectional area is greater than just squashing the original pipe diameter. You have to give the designers some credit, and it certainly wasn't their intention to restrict the performance of the car!
I've measured the actual cross sectional area and to be honest there isn't much difference between the squash and two small diameters a'la Larini. The performance gain is more due to removing the restriction of the cats to more free flowing 200 cell ones.

 

[maverick]

Check the yellow pages for a laser cutters, Spartacus has done the drawings for the flanges, you can contact him for this.

You need to find an exhaust fabricator, I am going to use Berkshire garage in Newbury which is a bit out for you. MIJ in walsall have some experience with maserati but I have read mixed reviews.

Also not sure if you are aware but the cats section of the exhaust swoops under the steering rack, the designers "squished" this section of pipe to restrict the performance of the car. Larini have their twin pipe solution but many have gone "fully round" on their custom cats and apparently have had no problems with ground clerence. At any rate there is a decent boost to the performance and throttle response for only £550

I got the drawings done for the flanges Sparts got them cut by a lazer cutters he uses .


This is what I had done at berkshire garage

 

[Yeti]

Spoke briefly with PD Gough in Nottingham. They can deffo do a straight pipe section, but when I get the car back from Shiltech I'm taking it round to see if they can fir a 200 cell cat in there. Got a feeling I might struggle with the MOT if I dump the cats altogether. Let you know ho9w I get on.

 

[FIFTY]

Good luck Yeti

...they actually increased the diameter of the exhaust at that point before squashing it, so the cross sectional area is greater than just squashing the original pipe diameter. You have to give the designers some credit, and it certainly wasn't their intention to restrict the performance of the car!
I've measured the actual cross sectional area and to be honest there isn't much difference between the squash and two small diameters a'la Larini. The performance gain is more due to removing the restriction of the cats to more free flowing 200 cell ones.

Did not know that, so they restricted the car with the ceramic cats and the intake..?

I got the drawings done for the flanges Sparts got them cut by a lazer cutters he uses .
View attachment 38180

Sorry Mav I did not realise you made the drawing. Can't wait to have mine done already. Going on holiday next week so hopefully I can get it fitted before festival italia

 

[Yeti]

Quick update regarding the exhaust saga. Seems the Larini pipes won't work because the light remains on. Shiltech are running out of idea's, and my local exhaust guy - PD Gough can do the rear cats (round) but not the front cats (oval) that run under the steering rack. Interestingly, with the car up on the ramp, there appears to be three sensors per side (see photo). Wondering if I could simply not fit the sensors to the front section and run a straight through pipe, remove the cat from the front cat box and refit the sensor, or snip the leads and join the cables? Anyone got any good idea's? They'll be gratefully received.

Incidentally, Eurospares list these pipes, but it's £1k for one side and over £2k for the opposite side. Go figure that one out because the pipes look to be a mirror image of each other.

 

[maverick]

Yeti pm me and I'll pm you my number there's no need to cut wires and the other sensors are temp probs only present in early cars I believe . To complicated to explain on a post but very easy in practise can explain on the phone would be so easy , please see the picture of my sport cat replacement using magnaflow 200 cell cats .

 

[Caldy999]

View attachment 38256

Can someone please tell me what the rearmost pair of sensors are for? The ones that look like brake pipes.

I'm having 200 cell cats fitted and the fitter was worried that he could not reproduce the fitting so if anyone knows the thread spec...

 

[CatmanV2]

*Should* be rear lambda sensors. The middle ones are thermocouples, apparently.

C

 

[Caldy999]

Yet the front 4 look identical, are situated immediately before and after the primary cats and as such are presumably lambda sensors but the rear 2, a matched pair but different to the front 4 are thus presumably temperature probes?

 

[CatmanV2]

Yet the front 4 look identical, are situated immediately before and after the primary cats and as such are presumably lambda sensors but the rear 2, a matched pair but different to the front 4 are thus presumably temperature probes?

The diagram is not exactly clear:

http://www.eurospares.co.uk/parts/maserati/4200-coupe/exhausts/exhaust-system-20129

But it looks to me that it's lambda / thermocouple / lambda

Front and rear lambda have different part numbers so it's quite possible that they are *all* different (which is actually what I think when I look at Mav's pictures)

C

 

[FIFTY]

I'm fairly certain only the 2002 classico has these heat probes. From the 2003 facelift it just has 4 lambdas...

 

[CatmanV2]

I'm fairly certain only the 2002 classico has these heat probes. From the 2003 facelift it just has 4 lambdas...

Looks like 2004 onwards so you're probably correct

C

 

[Caldy999]

Mine is 2002 so has these. Anyone know the spec of the fitting or of anywhere to purchase them?

 

[CatmanV2]

Any dealer?

C

 

[Spartacus]

Yes thats right . The face lift 4200 s only have 4 lambdas and no heat sensors