is250 Suggestions on a new exhaust

Mitcheyfex · August 10, 2020

Hope everyone is well!

Greetings from the UK, I'm still fairly new to this group, I picked upa second hand Lexus IS250 fairly cheap and I'm mostly impressed.

However, while driving the right exhaust came our of the centre pipe while driving and an inspection confirmed it had been welded, and quite a terrible job I might add!

Anyway, I wondered if anyone has ever had to replace their exhaust or upgraded the standard stock exhaust and what you went for?

Also, any suggestions as to where I might look? I have a Lexus IS250 2006, and the exhaust is a twin pipe coming from the centre.

Any help appreciated!

JamesIS220 · August 10, 2020

3 hours ago, Mitcheyfex said:

Hope everyone is well!

Greetings from the UK, I'm still fairly new to this group, I picked upa second hand Lexus IS250 fairly cheap and I'm mostly impressed.

However, while driving the right exhaust came our of the centre pipe while driving and an inspection confirmed it had been welded, and quite a terrible job I might add!

Anyway, I wondered if anyone has ever had to replace their exhaust or upgraded the standard stock exhaust and what you went for?

Also, any suggestions as to where I might look? I have a Lexus IS250 2006, and the exhaust is a twin pipe coming from the centre.

Any help appreciated!

eBay, may need a bit of modification, ie not quite lined up in bumper cut outs. Cheap. Rear section from Y pipe. https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=lexus+is250+exhaust&_sacat=0

Or custom made in stainless by exhaust place.

James.

Mitcheyfex · August 11, 2020

21 hours ago, JamesIS220 said:

Ebay, may need a bit of modification, ie not quite lined up in bumper cut outs. Cheap. Rear section from Y pipe. https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=lexus+is250+exhaust&_sacat=0

Or custom made in stainless by exhaust place.

James.

Hi @JamesIS220,

Thanks for your response, the link you sent me is actually quite good, a lot cheaper than I thought.

I think I'm going to try get this welded, and if something goes wrong again I will certainly look into one of these.

Exhaust place could also be worth a try but they'll probably charge a fair bit.

JamesIS220 · August 11, 2020

1 hour ago, Mitcheyfex said:

Hi @JamesIS220,

Thanks for your response, the link you sent me is actually quite good, a lot cheaper than I thought.

I think I'm going to try get this welded, and if something goes wrong again I will certainly look into one of these.

Exhaust place could also be worth a try but they'll probably charge a fair bit.

No probs 👍. If it can be welded would give it a bit longer and know the fit is good. Stainless custom job is the way to go. It just depends how long your going to keep the car.

Hope the welding works out.

James👍

Mitcheyfex · March 14, 2021

Sorry to revive an old thread.

The weld went well, but I also now have other holes in the exhaust and taking it to a garage they have advised I need a new back pipe mid section and cat.

I read today that catalytic converters are being targeted by thieves because the value of the metal inside these cats is more valuable than Gold currently.

What is stopping me selling my cats in order to obtain enough money for a new exhaust system? Would that work? Or is it a stupid question.

Thanks in advance

Linas.P · March 14, 2021

The metals in cats are Platinum, Palladium and Rhodium and they have always been more expensive than Gold. Selling your old cats would not buy you an exhaust system, assuming you can find who buys it the cost of used catalytic convertor will be ~£80, your car has 4 of them, so ~£320... still nowhere near the price you need for exhaust replacement.

Besides removing cat is illegal and your car will fail MOT without one, not to mention it would be immoral to pollute without any good reason.

The main question I have - does your car actually need entire system or is it just mechanic trying to make a profit from you? My old IS250 had some rust on exhaust, pretty much all the time I have owned it, but that was mainly back section (reproductions or SS custom made ones could be had for £300). In the mid section it had one small hole near the resonator (common place to fail) and still has it as far as I know. The mid-section is easy replacement because it is basically 2 straight pipes joining into Y at the end - any pace should be able to do it very cheaply (under £200). I have never seen front section and especially cats needing replacement - so my suspicion machinic either does not known what he is talking about or trying defraud you.

Get second opinion first (if you cannot check yourself), because it doesn't seem likely to me that car needs entire exhaust system.

KenMavor · March 14, 2021

11 minutes ago, Mitcheyfex said:

Sorry to revive an old thread.

The weld went well, but I also now have other holes in the exhaust and taking it to a garage they have advised I need a new back pipe mid section and cat.

I read today that catalytic converters are being targeted by thieves because the value of the metal inside these cats is more valuable than Gold currently.

What is stopping me selling my cats in order to obtain enough money for a new exhaust system? Would that work? Or is it a stupid question.

Thanks in advance

Get a new stainless steel one built for your car. You can go cat back or whatever or remove the cats underneath the car....there are 4 in total but the front two are part of the exhaust manifold and very difficult to get to by anyone. Unsure if removing the two cats underneath the car is a MOT fail but someone will be along soon to confirm or deny. Cost wise to replace the middle section, and keep the cats, probably about 250 to 300. The rear section is about another 600.

Linas.P · March 14, 2021

9 minutes ago, KenMavor said:

Get a new stainless steel one built for your car. You can go cat back or whatever or remove the cats underneath the car....there are 4 in total but the front two are part of the exhaust manifold and very difficult to get to by anyone. Unsure if removing the two cats underneath the car is a MOT fail but someone will be along soon to confirm or deny. Cost wise to replace the middle section, and keep the cats, probably about 250 to 300. The rear section is about another 600.

SS are likely to drone... if OP want's to "show-off" a bit then why not - IS250 actually sounds great with SS system, but then you will need to live with drone.

Technically any modification to emission equipment is MOT failure, whenever removing secondary (lower) cats and leaving primary (upper) ones would pass mot is kind of a guess game. I would argue that as long as car passes emissions test and still has primary cats it should be road legal, but that will be decision based on MOT tester discretion. Cats in IS250 are not restrictive anyway and removing them adds nothing to the car so I would advise to leave them in place.

Mitcheyfex · March 14, 2021

Thanks for the responses guys, very informative and I really appreciate all the info.

Apparently modifying anything to do with emissions is technically illegal and supposed to be an MOT failure however most independent garages just go off the emissions read out and if it passes the emissions test they are usually satisfied, I have heard of a few lexus owners removing two of the cats and still being able to obtain an MOT.

I'm looking for a system which isn't too loud and offensive but has a nice deep tone (not the kind that would wake the neighbours up) possibly a resonated system? Please confirm if correct or incorrect.

But that does answer my question in full and I really appreciate that, and following on from this I will get a second opinion, because replacing the mid and rear section will be considerably cheaper than replacing the whole exhaust.

I have actually found a second hand exhaust system it is completely standard though but the guy only wants £120 for it, it is however quite rusty but no signs of weld or any holes whatsoever, is there any issues buying an exhaust system with rust, and could it pose problems down the line.

Thank you again guys

Linas.P · March 14, 2021

The problem with SS is that metal itself is different and it resonates much more, the walls on SS exhaust are usually thinner as well - and that overall results in drone at any constant load/speed.

Not really sure what you mean by "resonated system" - I guess you can call original system that, because it was designed in a way to minimise resonation and drone from the factory - that is very long and expensive process costing millions to design the system which effectively silences the engine and eliminates any unwanted resonations. No aftermarket exhaust will ever get to that level, unless well known mass produced like HKS, but good luck finding HKS system in UK (it is impossible).

Exhaust has it's lifetime, so the used exhaust will last the remainder of it's life, paying £120 may be a good value and it may last several years. The outside surface rust is not an issue, but exhaust usually rusts from inside, so it is very hard to tell if it is in good shape.

johnbiker7 · March 14, 2021

Hi everyone ,

I've recently replaced the centre section on my IS250.It came all in one piece complete with the afore mentioned cats, off eBay. Cost was £397, supplied by a motor factors in Bilston West Midlands. If I remember correctly it was a Euroflo system. Had it fitted locally at exhaust specialists at cost of £160 including new bolts and gaskets,they said it was one of the most difficult exhausts they have fitted. They had to cut every nut and bolt off with cutting disc. I'm glad I decided not to DIY and I was a maintenance Tech / Engineer all my working life, but at 73 you do eventually have to draw the line somewhere .

John

Linas.P · March 14, 2021

8 minutes ago, johnbiker7 said:

They had to cut every nut and bolt off with cutting disc.

Sounds exactly like every single 10 years old exhaust job 😁

It is possible to undo the bolts, but it is certainly quicker just to cut them.

KenMavor · March 15, 2021

16 hours ago, Linas.P said:

SS are likely to drone... if OP want's to "show-off" a bit then why not - IS250 actually sounds great with SS system, but then you will need to live with drone.

Technically any modification to emission equipment is MOT failure, whenever removing secondary (lower) cats and leaving primary (upper) ones would pass mot is kind of a guess game. I would argue that as long as car passes emissions test and still has primary cats it should be road legal, but that will be decision based on MOT tester discretion. Cats in IS250 are not restrictive anyway and removing them adds nothing to the car so I would advise to leave them in place.

SS are likely to drone... if OP want's to "show-off" a bit then why not - IS250 actually sounds great with SS system, but then you will need to live with drone.

Always seen this quoted as an issue and when I got mine done I said to the fitter that I do not want the exhaust to drone. I want it to be as silent as the OEM one on it. He then did some tweaking to pipe sizes and it is throaty but does not drone at all.

Linas.P · March 15, 2021

7 minutes ago, KenMavor said:

Always seen this quoted as an issue and when I got mine done I said to the fitter that I do not want the exhaust to drone. I want it to be as silent as the OEM one on it. He then did some tweaking to pipe sizes and it is throaty but does not drone at all.

This is always quoted as an issue, because about every single person who get's SS exhaust later comes back to complain about drone. Sound like you have best of both worlds then.

KenMavor · March 15, 2021

4 hours ago, Linas.P said:

This is always quoted as an issue, because about every single person who get's SS exhaust later comes back to complain about drone. Sound like you have best of both worlds then.

I think being aware of the potential issue before getting the exhaust done gave me the questions to ask and to make sure they guys building the exhaust didn't just do a like for like replacement. I know they changed the diameter of the pipe on the rear section.

Mitcheyfex · March 15, 2021

Question regarding changing the diameter of the rear pipe.

Would this affect performance gains because your technically limiting air flow?

Linas.P · March 15, 2021

4 minutes ago, Mitcheyfex said:

Question regarding changing the diameter of the rear pipe.

Would this affect performance gains because your technically limiting air flow?

It could, depending where it is done, but generally IS250 exhaust is not restrictive. Other questions is whenever the OD or ID was changed. It is possible that smaller OD SS pipe may still have same IS as mild-steel, because SS pipes tend to have thinner walls.

Mitcheyfex · March 15, 2021

44 minutes ago, Linas.P said:

It could, depending where it is done, but generally IS250 exhaust is not restrictive. Other questions is whenever the OD or ID was changed. It is possible that smaller OD SS pipe may still have same IS as mild-steel, because SS pipes tend to have thinner walls.

OD or ID?

Thanks for all of your help on this! I'm debating on just waiting it out to see if I can get an OEM exhaust system second hand, and dealing with trying to get a slightly deeper tone later on down the line.

By resonated I mean a system with a resonator on it, I was told this would still be fairly quiet but have a nice subtle tone when accelerating.

I really like the Tenabe exhaust system but I just don't think I can afford it at the moment, but that would be my ideal exhaust system by what I've seen and heard.

It sounds terrible at the moment and really doesn't feel like it's 206bhp, so anything will be a substantial improvement.

Mitcheyfex · March 15, 2021

Also, I do have the service video from Lexus Gatwick which does show the holes on the exhaust, I'm happy to send this video to anyone that might be able to tell me what I need and whether or not indeed I do need th front section and new cat.

Tia

Linas.P · March 15, 2021

I doubt holes in exhaust impact HP at all. You system does have resonator (that is long tube where where double exhaust meets in Y over the axle).

When you look at Tenabe, just be careful, because most of the videos are from IS350 and IS250 obviously does not sound similar at all.

Mitcheyfex · March 15, 2021

24 minutes ago, Linas.P said:

I doubt holes in exhaust impact HP at all. You system does have resonator (that is long tube where where double exhaust meets in Y over the axle).

When you look at Tenabe, just be careful, because most of the videos are from IS350 and IS250 obviously does not sound similar at all.

Thanks for your response.

Are you sure? Every garage seems to assure me that holes in the exhaust system does affect performance and it definitely feels less 'sharp' than when I bought it.

Yes, I made sure to look at the IS250 videos, I also watched some of the IS350 ones and oh my 🙂

Linas.P · March 15, 2021

1 minute ago, Mitcheyfex said:

Thanks for your response.

Are you sure? Every garage seems to assure me that holes in the exhaust system does affect performance and it definitely feels less 'sharp' than when I bought it.

Yes, I made sure to look at the IS250 videos, I also watched some of the IS350 ones and oh my 🙂

When it comes to horse power... I doubt that even straight piping or removing exhaust all together would impact IS250 in any meaningful way.

However, some backpressure could add some low end torque, still I would be amazed that few holes in exhaust would have noticeable effect.

By the way - OD/ID is outside/inside diameter of the pipe.

Mitcheyfex · March 15, 2021

Just now, Linas.P said:

When it comes to horse power... I doubt that even straight piping or removing exhaust all together would impact IS250 in any meaningful way.

However, some backpressure could add some low end torque, still I would be amazed that few holes in exhaust would have noticeable effect.

By the way - OD/ID is outside/inside diameter of the pipe.

Fair enough, good to know.

Kind of a bummer because something is definitely effecting the performance, I know spark plugs are due to be done and it could do with a carbon clean perhaps? Just some ideas circulating.

Thanks for clarifying that, appreciate it.

H3XME · March 17, 2021

On 3/15/2021 at 3:34 PM, Mitcheyfex said:

Fair enough, good to know.

Kind of a bummer because something is definitely effecting the performance, I know spark plugs are due to be done and it could do with a carbon clean perhaps? Just some ideas circulating.

Thanks for clarifying that, appreciate it.

Here's what I did. I got HKS axle back for my IS250. This is the sound >

There is 0 drone. I'm booked in for a secondary de-cat soon. I'm hoping it won't make it much louder, I just want a slightly better flowing exhaust gases and slight bump in torque. Cat on IS250's are not actually worth that much. I was quote like £70 per secondary cat. Not surprised they aren't that good considering how much we have to pay for road tax with manual cars.

Mitcheyfex · March 17, 2021

2 hours ago, H3XME said:

Here's what I did. I got HKS axle back for my IS250. This is the sound >

There is 0 drone. I'm booked in for a secondary de-cat soon. I'm hoping it won't make it much louder, I just want a slightly better flowing exhaust gases and slight bump in torque. Cat on IS250's are not actually worth that much. I was quote like £70 per secondary cat. Not surprised they aren't that good considering how much we have to pay for road tax with manual cars.

This is exactly the kind of sound im looking for!

HKS exhausts are so expensive though.

Thanks