V6 exhaust explained please
 

Hi folks

I have a 2.5 v6 club de x-reg, I’m told the exhaust system is old and needs replacement and that it has two catalytic converter on it, so to avoid being taken advantage of would someone explain to me where they are so I can see for myself.
Any help is good help so thank you in advance.

https://rimmerbros.com/Item--i-WCJ000391SLPP
According to rimmers it has one catalytic converter :}
Shud have scrolled further down it does indeed have two, I will stick to diesel questions in future:duh::getmecoat:

Hi Timothy,There's a photo of the front pipes and catalyst assembly here: https://rimmerbros.com/Item--i-WCJ000391SLPP

EDIT: The second catalyst is part of this assembly (Item 8) https://rimmerbros.com/Item--i-GRID001949



TC

If they recommend you replace the cats make sure you get them. They are most likely worth £500-£600. The cats shouldn't need replacing.

I'm not so sure there is a 'second' converter, if so perhaps someone who said there was can explain what the second one does? No point in putting pre and post oxygen sensors on the first cat if the second one is just another box of rare earth metals 'cos the O2 sensors are comparators for measuring output gases and in that case the sensors would be on the second cat. The only time you will have two cats is if there are two separate (dual) exhaust systems or one that merges post cat.
Might be wrong but the KV6 intermediate section has a pair of in-line mufflers and then there is a [separate] rear silencer box.

My V6 2.5 is booked in for Tuesday for catalytic convertor replacement. The garage was adamant the catalytic convertor had 'blown'. Maybe I'll ask them to keep the old part so I can see what failed?:shrug:

there are two cats on it. i replaced mine years ago for an aftermarket , when i did the LPG conversion. i kept the old one in the shed. they are stainless and stamped with their manufacture checked serial number on each cat, and are logged. about 12 mths ago i decided to have a clearout in the shed and put it on ebay. i asked £175 for it . and should have asked a lot more. as soon as posted before my kettle had boiled , it was sold . !!! this was downpipes and two cats only. they are indeed worth a fortune now. so if i were you i would tell the garage you want the cats back. people online will come out to collect it for free and buy them these days from you. the precious metals content in them are becoming rarer and rarer. some people get the price of a new exhaust out of it. ... ;)

There's a precat where the 6 into 3 into 1 meet which seems to do the majority of the work, along with the later main or slave cat as I call it.

My last v6 main / slave cat I weighed in gave me nearly £300 cash, which was circa 2016 but still and it was absolutely wrecked and rattling, but still had the code and bits in it.

Personally I'd look for a complete 2nd hand system from someone in the club. Sake of a few bolts and half an hour of fiddling under a jacked up car it's an easy DIY, and if you give then your old system they can weigh cats in and not loose out making a fair price all round.

Clarification: catalytic converters
 

Rimmer's has reproduced an ambiguous description from the MG Rover/X-Part Electronic Parts Catalogue.
RAVE shows item 8 as comprising three silencers; front, intermediate and rear. It has no catalytic converter.

The "starter" catalytic converter is the easily missed short bulge with a lattice surface visible in WCJ 000391SLP just downstream of the downpipes joint. The second converter is the torpedo shaped component and this will have the lambda sensor mounted at its output. Both converters are integral with the downpipes assembly.
That sounds like a highly dubious diagnosis to me. What does "blown" mean? :rolleyes: If your "check engine" light is on the cause is most likely to be related to fuel, spark or combustion.
That's ridiculous Tim. Is your "check engine" light on? Is your exhaust holed anywhere and leaking gases?

Simon

Why do they say it has failed? Has it failed the MOT on its emissions as V6 cat failure is very rare and if they are fitting an aftermarket part then it will most likely only last for a year and due to them not being very good you will possibly end up with the engine light on and code p0420 due to catalyst performance

if you do have a new one fitted make sure you get the old one back

Dave