IS 250 exhaust

[KenMavor]

IS 250 that I had just bought needs a new middle and rear section of exhaust. Total price for a new Lexus exhaust, from engine to rear, is about 3k. Ha ha. Garage I bought the car from gave 2 months warranty but do not, and I agree, want to put a £3k exhaust on a car that didn't cost that much more. They have offered a contribution to a new centre and rear section. I want to do it in stainless steel as the quotes I have had are around £700 and the garage are happy to cough up £600.

Question is this.....the centre section has two sensors and I suspect two cats and one stainless steel company have said they would remove that those and just put straight pipes in there. Another company said they'd leave those in and do what I surmise is a cat back system. I am presuming taking the two sensors out, which maybe a problem anyway, and the two cats will probably affect the running of the car and possibly give me engine management light problems which I am keen to avoid.

What is everyone's recommendations?

Thanks

[mk_lon]

I'm not an expert but I'd recommend going on eBay and getting hold of a second hand exhaust as I've been told in the past that stainless does not suit the cars character (too loud). 

[johnatg]

Certainly don't remove the cats. The sensors are downstream oxygen sensors - less important for running but if they're not connected I think you'll get engine management light problems, so don't remove them either. A catback system should be OK, but specify that you want a guarantee that it will be as quiet as the original as many stainless systems are noisier.

You can get a soundmeter (decibels) app for your smartphone!

[KenMavor]

22 minutes ago, johnatg said:

Certainly don't remove the cats. The sensors are downstream oxygen sensors - less important for running but if they're not connected I think you'll get engine management light problems, so don't remove them either. A catback system should be OK, but specify that you want a guarantee that it will be as quiet as the original as many stainless systems are noisier.

You can get a soundmeter (decibels) app for your smartphone!

Sounds like good advice but with a hole in the centre section growing bigger daily and it now sounds like a tractor so have no baseline to measure a new stainless build against!!

Beginning to agree with the cat back idea...leave sensors and cats in place and replace everything else behind.  Should be the simplest way of doing it.  Can probably live with a slightly louder exhaust but if stainless used but that should be the exhaust sorted for the life of the car.  Another second hand rear exhaust section (maybe 8/9 years old) could easily rust and deteriorate and then I'm back to square one.

[is200 Newbie]

I am sure in deleting the cats it will be an MOT failure.

Removing the sensors will certainly throw up errors and give you issues with running the car as, if I am not mistaken, these down stream ones act to adjust the running of the car to ensure the gasses coming from the cats have been reduced to an acceptable level - this wont be possible if there's no cats and it wont run correctly.

The existing sensors can be fitted to a stainless system with no issue - the issue I had with the stainless one I had fitted was the noise generated by it, especially in the cabin. The issue on mine was a very loud drone at 70mph.

I had a cat back on mine (centre and boxes) after the centre box joint went. Got rid of it due to the noise it created. If you going down that road, make sure the garage keeps the old system until you are happy with the stainless one as it can always go back on until a quiet exhaust can be sourced. As mentioned above, look on eBay for good used one as in my opinion it may be the better option. It seems the OEM ones are made from a better steel than mild and do last a while (in most cases !!)

[Linas.P]

In terms of making for SS for middle and back section I believe it is not that great idea, unless you like your car to drone. Best of both worlds is mild steel mid section and SS rear. Removing Catalyst converters is same as removing DPF - it is illegal and punishable offence... and I agree - you just convert your car into pollution factory for no good reason.

[bobmc]

I see lots of 3rd party exhaust options on eBay these days

Would one of these not be suitable for middle section

http://www.ebay.co.uk/itm/Lexus-IS250-2-5-05-13-Approved-Petrol-Exhaust-Catalytic-Converter/172856116928?hash=item283f0706c0:g:3KwAAOSwIwhWTtvK

and this as a back section

https://www.ebay.co.uk/itm/LEXUS-IS250-SALOON-2-5-PETROL-RWD-2005-2008-REAR-EXHAUST-SILENCER/112521866538?epid=2169258537&hash=item1a32d36d2a:g:Q5IAAOSwVbtZjsqD

 

[KenMavor]

11 minutes ago, bobmc said:

I see lots of 3rd party exhaust options on ebay these days

Would one of these not be suitable for middle section

http://www.ebay.co.uk/itm/Lexus-IS250-2-5-05-13-Approved-Petrol-Exhaust-Catalytic-Converter/172856116928?hash=item283f0706c0:g:3KwAAOSwIwhWTtvK

and this as a back section

https://www.ebay.co.uk/itm/LEXUS-IS250-SALOON-2-5-PETROL-RWD-2005-2008-REAR-EXHAUST-SILENCER/112521866538?epid=2169258537&hash=item1a32d36d2a:g:Q5IAAOSwVbtZjsqD

 

Been looking at the rear section bit but probably going to get a cat back stainless steel set up and make sure I get the quietest noise possible.  I have already purchased a second hand center section and will keep that in case the stainless steel version is too loud so all I would have to buy is the rear section.

[65mike]

Hi all.

Being new to the Lexus brand off cars and this being my first is250 was a little surprised regarding the exhaust needing replacement.

My question therefore is, is this a common thing that the exhaust fail on these cars as i have seen by other posts that they are expensive.

Seems strange that today with all the engineering they put into cars that they cannot / will not make a exhaust last a lifetime as standard fitment.

I have not replaced a exhaust in nearly 13 years as the Jaguar system was very robust made off stained steel not great grade S/S but did not give up the ghost.

I think a S/S would be the best option but it would probably be louder and probably drone as is200 Newbie says.

In my view the more noise and droning would not be acceptable the reason i brought the is250 was it was so quiet and refined and that would take it away in my view.

My previous car was a XK and that had a loud exhaust but was fitted as standard when built came with it.

65mike

[Linas.P]

Quick answer to your questions:

Is it common? - on 10 years old cars, yes it is. Most often surface rust, but mine has cracked in one place and I opted for it to be welded back for £60. It wasn't badly rusted, but kind of combination of surface rust and crack on the weld. I am not that surprised either, cars are not designed to last forever nowadays and exhaust sytem lasting ~10 years is reasonable.

How expensive is OE replacement ~£3000 (I believe original price was something along the lines of £3800, but now dropped to £2800, £2000 middle section, £800 rear section)... Now that is unresonable

It is not made from SS, because SS tends to drone - just a natural property of the metal + thin wall pipes.

How big of an issue? - you likely need to replace rear section, it tends to crack + rust around Y section and near rear silencers. Middle section most often has only surface rust and as far as safety and the rest goes it is unlikely that it would need replacement.

The rear section can be made from SS and if properly made will drone minimally, I would advise against replacing middle section with SS. So if you about to replace something - get middle section in MS and rear section in SS, but make sure it is the most silent one you can get.

Cost ~700-800 for aftermarket system, rear section can be found from £290, SS maybe little bit more expensive ~£400.

[65mike]

Hi all.

Linas thanks for the info i now see why the dealer said the exhaust is not covered by the warranty as it is a expensive item which they do not want the cost off replacing so it comes under the ware and tear heading.

Will need to look into it further as and when it needs doing but should get hopefully a lot more out off it yet as the mileage is only 29000 miles 

65mike

 

 

[KenMavor]

Anyone else out there done anything....can't believe only 2/3 people have had to replace their exhaust and cannot think that most have gone OEM for the price.

The drone problem worries me but then again so does having to replace another mild steel exhaust section a couple of years down the line if the second hand parts I get get rusted through again.

 

 

 

[is200 Newbie]

9 hours ago, KenMavor said:

Anyone else out there done anything....can't believe only 2/3 people have had to replace their exhaust and cannot think that most have gone OEM for the price.

The drone problem worries me but then again so does having to replace another mild steel exhaust section a couple of years down the line if the second hand parts I get get rusted through again.

 

 

After I took the stainless one off I made my own - used Rover back boxes and an IS200 centre box - along with pipe I bought - the car is back to being quiet again. Each boxes are twin outlets - the tips were found on the web.

To be honest, if you like to get your hands dirty and can weld a bit then its not a hard job. Picture of mine below. I still need to do a diffuser or mould round the bumper exhaust outlets but  just not got round to it yet. I put it together so I could replace each section so when it goes in the future I will change the whole lot or just the individual piece.

 

[Linas.P]

11 hours ago, KenMavor said:

Anyone else out there done anything....can't believe only 2/3 people have had to replace their exhaust and cannot think that most have gone OEM for the price.

The drone problem worries me but then again so does having to replace another mild steel exhaust section a couple of years down the line if the second hand parts I get get rusted through again.

As far as I know, now most of the places use "aluminised" steel, I doubt that completely mild steel is still widely used nowadays (the thing which rusts straight through in 3 years).

https://en.wikipedia.org/wiki/Aluminized_steel

It does not rust from outside and only burns down from inside slowly (or is dissolved by various chemicals in exhaust) , it is cheap and does not drone. Should be pretty close to what it was from factory and should last for another 5-8 years for a fraction of the price. That again mostly concerns middle section which is amazingly expensive. As for rear part I have nothing against SS, but you need to specifically ask for silent one... and well... trust the guys who are making it as such.