iyad.2010

Hi sup guys

i was wondring if i deleted the cats on my s600 biturbo

and make it a straight pipe

am i gonna get any problem with it ?

i know i well get check engine light i can turn that off via star

any other problem ? my car is 100% stock no ecu tune



thanks

terrance21!

As long as you weld on O2 bungs for your sensors you should be free of any CEL. Only problemwould be if you live in a state with inspections you will fail miserably! Good luck.

iyad.2010

hi terrance what is the o2 bungs ?
i live in ksa so no problem

should i put the sensors in the straight pipe or delete it

sorry i am not very experinced in the exhaust

terrance21!

Your O2 or oxygen sensor measures the amount of oxygen in the gas coming out of your exhaust. If the calculation is thrown off that is when you will get a CEL. You can get rid of your catalytic converters but your ECU will still have to read the O2 levels. If you go to a reputable exhaust shop the will know what to do.

S600Keith

OMG!! That is SOOO not the case here in California. Wish we could get away with that...

Terrance's advice is sage advice indeed. Go to a reputable shop and they will know how to bypass the sensors/CEL.

123Pokey321

On other vehicles (Passat), there is a way to eliminate the secondary O2 sensor after the cat and it involves using a resistor. You may want to ask a local shop if they are aware of this technique.

Dr. Tune

Has anybody actually done before and after dyno pulls to see what, if any gains in HP and torque are?

Or is this a exhaust sound changing mod?

jay.n.bannister

Hi long time reader first time poster.
Id also love to speak to someone with experience removing secondary cats and/or primary cats from the s600. Did you butt dyno or even better a real dyno notice any differences?

tusabes

You'll get more power from a tune than by deleting cats

My position has always been to
Leave your cats alone unless they need replacing . That's a good time to delete them.

Keep in mind you might get much less at trade in and won't be able to resell your car out of state to a state with smog checks, if that's important to you ,

jay.n.bannister

Great to know! Anyone deleted the secondary cats off an 03 - 06 s600?

iyad.2010

guys nevermind i left the cats just the way it is

but i deleted the second cat now turbos breath better and spin faster i recommend this to all s600 owner

then after a month i did a cutout before the muffler and it sound greet much like a 65

and turbos spin even faster esp keeps blinking

shardul

iTrader: (1)

i got rid of my primary cats and let me tell you this is a must, My boost is about 22psi before it starts to taper down. The car sounds amazing too!
The M275 S600 V12TT has only one set of cats that are right after the turbos. They dont have any secondary cats.

jay.n.bannister

I ended up gutting the cats along with the ecu/tcu tune. Average fuel consumption dropped by 10% and feels better. Sounds more turboish so im going to cutout rear mufflers hopfully give it a little more engine sound rather than turbo, see how it goes.
Highly recommend gutting the cats to anyone considering it. I originally expected it to have primary and secondary like all other mercs ive had however it only has primary cats right after the turbo as someone else mentioned.
Not sure if it would make a CEL appear on a non ecu tuned car that hasn't has the after cat o2 sensor disabled though.
I think this mod is almost as essential as an ecu tune as the cats appear to be the only thing making the exhaust not a complete free flow open system, the rear mufflers do not even have baffles in them.

shardul

iTrader: (1)

what psi does your boost spike up to before it starts to drop?
I have deleted my rear muffler but kept the resonators in place and the car is loud. if you drive it daily it will get annoying.

jay.n.bannister

Mine holds about 19psi all the way to the top at WOT.
Rear muffler delete is not going to be an option then this is the car I cover a lot of km's in while using phone/talking! Maybe look into replacing the rear mufflers with something smaller or ever dropping the resonator. Try and find that sweet s65 sound which is in between the church mouse s600 and your car with no mufflers.
Amazing its so quite with straight though rear mufflers and resonators though, shows how tiny the turbos are to muffle the sound so much.

shardul

iTrader: (1)

what you can do to help performance a bit is make the exhaust a dual. you will see in the 600 2 pipes merge into 1 and back to 2.

jay.n.bannister

I saw the mixer and for oem standards its a work of art!

iyad.2010

but i had somthing before the muffler i dont know what its called

is it a cat or resonater i dont know the diffrence between them

jay.n.bannister

not sure, my s600 had twin cats (one for each bank) which ive deleted/removed. The exhaust then goes into a square mixer, splits back into twin pipes where each side has a resonator, followed by a muffler (non baffled and straight through).

Having no baffle/restrictions whatsoever in the resonator or mufflers I don't see how removing/deleting the mufflers could possibly result in a higher power output like removing the cats does.

iyad.2010

removing the mufflers makes the turbos breath better

jay.n.bannister

it would if it was baffled/restricted however its not, its just like a large glasspack

shardul

iTrader: (1)

you all know that the main restriction is the primary cats right? all the mufflers and resonators are way down stream in the exhuast system and removing them provides neglegible and non quantifyable gains.

jay.n.bannister

Yes, very aware of this esp when you can insert a garden hose several meters into the exhaust without any obstacles.

biturbine

How much power do you gain more or less from gutting the cats?

Does my eurocharged ecu need to be reprogrammed after doing this?

jay.n.bannister

Personally I cant quantify the hp gains however id guess it to be around 20-30hp? Who knows, get a re-tune a specify that you have gutted your cats.