Yet Another Exhaust Thread!

[MAF260]

FYI there is a member on the maserati club uk site who is asking for some replacement factory cats if you want to move them on.

Would you please let me have the details, Pete. I have a pair from my GS taking up space in my garage and I need to have a clear out before I sell the house.

 

[safrane]

https://www.maseraticlub.co.uk/market/market-list/details/53/

As mentioned Maf

 

[Caldy999]

They look great Caldy. Let us know what you think of the throttle response when you get to drive her properly.

Definitely sharper, especially at the bottom end. The 'wooliness' has gone, it sounds very tonal but not too loud, and it goes like stink!

 

[mchristyuk]

Ok I've finally got round to doing mine.. I've done the same as Caldy, but in a cheaper way

Fitted the forum X-Pipe, but instead of replacing the front sections I've had the primary cats gutted. We then added some O2 sensor cheaters to stop the CEL being thrown and much less hassle than getting the ECU reprogrammed.

So far my experience is the same as Caldy's.. much sharper throttle, pulls better, only marginally louder though. Get a few nice cracks on over run occasionally though!

Probably need to look at doing something with the back boxes now I think.... hmmmm..

Mark

 

[miket]

"Sensor cheaters" what & where are they from? And if they only fool the ECU what will Mr MOT find when checking emissions?

 

[Fat Arnie]

MOT testers cannot tell if there is a cat on the car or not through exhaust analysis. My Caterham has a bypass pipe fitted as the cat robs power. There are many more like mine. They never even spot its missing, which is odd as on a Caterham its on the outside of the car!

 

[mchristyuk]

"Sensor cheaters" what & where are they from? And if they only fool the ECU what will Mr MOT find when checking emissions?

Mike,

The first set of O2 Sensors sort out your emissions, the second set after the CAT just let the ECU know whether your CAT has failed or not. So if you "bypass" your primary CAT as I have done you need to do something with the sensors.. most people either flash the ECU or move them to after the second CAT. The simpler option is these:

http://www.ebay.co.uk/itm/122125474436?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

All they do is move the sensor out of the gas flow so that it sees less exhaust gas.. the ECU compares before and after and gives the emissions the thumbs up

Mark

 

[Evo Cymru]

Hi Mark,

I'm planning to do this to my Gransport - can I just ask how you went about gutting the primaries? I remember Craig posting on the American Maserati site how he cut his open (very carefully!), removed the cats and then welded up neatly - did you use the same method?

Thanks

Oliver

 

[mchristyuk]

Hi Mark,

I'm planning to do this to my Gransport - can I just ask how you went about gutting the primaries? I remember Craig posting on the American Maserati site how he cut his open (very carefully!), removed the cats and then welded up neatly - did you use the same method?

Thanks

Oliver

Hi Oliver,

Not exactly...

In the USA they're not allowed to mess with the CATS by law.. so.. Craig was very careful how he cut them open so he could hide is tracks. We on the other hand don't need to worry about such things so can be a little less picky with where we cut things open. The rest is second hand as it's as my mechanic described it to me.. so apologies for inaccuracies.. My guy discovered (just before he started cutting luckily!) that quite a bit of the exhaust is Titanium around there.. so would have been a b!tch to weld back up. There appears to be a nice "window" which is steel around the centre of the CAT.. so he cut a window there and stripped the material out through that.

Either way it seemed a pretty easy job. Car is certainly more lively on the throttle now even if it's not that much louder.. though the odd crack on overrun out the back is quite loud!

Cheers

Mark

 

[Evo Cymru]

Cheers Mark, that will be very useful. Plan to speak to my exhaust guy in the next week or so. Crack on overrun sounds cool! Now H pipe or X pipe...???

 

[CatmanV2]

Hi Oliver,

Not exactly...

In the USA they're not allowed to mess with the CATS by law.. so.. Craig was very careful how he cut them open so he could hide is tracks.

Was this his GS? It doesn't sound that loud.....

C

 

[BennyD]

Cheers Mark, that will be very useful. Plan to speak to my exhaust guy in the next week or so. Crack on overrun sounds cool! Now H pipe or X pipe...???

H-pipe; the cracks and bangs come out in stereo! ;D