RX400h cat theft + relay theft

06_400_h_se · October 27, 2019

Hi,

I previously posted up about a phantom theft that was going on from my 2006 RX400h. I'd find the car had been entered at some point during the week or overnight (only really use at weekends) and loose change, etc. stolen. This has stopped now since I've started putting the keys away in a shielded tin, so I guess this was a relay attack.

Also, more recently, my cat was stolen. I know there are many threads on this already, but thought I would post up my story if it helps. The RX seems to be popular because apparently hybrid cats can fetch more for scrap (and the RX is easier to get under I guess). Whether this is true or not, it's still a popular target with thieves.

Anyway, looking at the design of the cats, we have one on each manifold and then this third cat/silencer unit at the back (in addition to the final silencer).

So, I've gone cat-less at the back and just had a straight pipe fitted. I can't honestly see any other solution as replacing it will just result in repeat thefts (it takes less than a couple of minutes). Hybrids don't require emissions testing at MOT (my MOT tester confirmed this) and it seems the manifold cats do the bulk of the work anyway (I can't find exact numbers, but some say around 80% is done up front). I'll report back when I go in for MOT and I'm going to ask him to test the emissions anyway to see what the impact is.

Sound-wise there is no difference and if anything the car is slightly more responsive.

I get that I could keep replacing the cat, but that's not realistic and the only other options is to sell the car. Also a dummy cat is pointless as the thief would cut the pipe anyway (most likely) before realising it's a dummy. Ditto with CCTV/alarms, etc - at best a possible deterrent, but not fool-proof.

Thanks

Herbie · October 27, 2019

I've spoken to two different MOT testers (both personal friends) and they say it's a very grey area and they would have to ask for guidance as to whether it would fail or not.

Technically it's an immediate fail if it should have a cat and it's been removed, but given that hybrids don't go through emissions testing anyway there could be an argument for it passing.

I think the government are going to have to make an official decision one way or the other.

Britprius · October 27, 2019

You cannot do an emissions test on the Toyota/Lexus range of hybrids because the engine cannot be made to run continuously with throttle control "holding the revs at a given level" the engine may stop running at any time. Further the emissions test is done with the engine off load, and this also cannot be achieved on a hybrid because the system will try to charge the Battery putting a load on the engine this applies even in service mode.

Under the regulations for the new MOT if a cat is removed or appears to have been cut open, and re- welded it is an instant fail if the tester believes the cat to have been tampered with. A small split or hole repair is acceptable, but obvious cutting open, and re-welding is not.

John.

Lager shandy · October 27, 2019

Just fit a fake empty cat looks the same and no mot tester is going to ask you to remove it to prove .

iwonder · October 29, 2019

It will pass the MOT without the center cat. Don't forget the RX has a cat in each manifold which is monitored so no EML. As mentioned above hybrids don't apply for the emissions testing therefore doesn't apply for the inspections related to that, which is checking the cat is fitted. Straight pipe or add in a silencer.

06_400_h_se · October 31, 2019

On 10/27/2019 at 4:45 PM, Lager shandy said:

Just fit a fake empty cat looks the same and no mot tester is going to ask you to remove it to prove .

Thanks, but this defeats the point, which is I suspects thieves would cut it out before realising it's fake. I think the only realistic option is this (or a garage and never park in public!!).

Lager shandy · October 31, 2019

Well your only option well in a pipe clean up welds it will soo rust and match the rest of the system .the mot tester unless he knows it should be will be oblivious to it just get it mot at kwik fit they will only be interested in your tyres and brakes lol .

katabrontes · November 2, 2019

How about getting the nuts spot welded to the bolt on the Cat connection. If it or the exhaust need changing it's only a minutes work with an angle grinder to cut the nut off but it would make it slow and noisy to steal it. Maybe a notice on a window alerting thieves or maybe one with "No cat on this car" might be a useful addition as well.

welland · November 3, 2019

On 11/2/2019 at 5:55 PM, katabrontes said:

How about getting the nuts spot welded to the bolt on the Cat connection. If it or the exhaust need changing it's only a minutes work with an angle grinder to cut the nut off but it would make it slow and noisy to steal it. Maybe a notice on a window alerting thieves or maybe one with "No cat on this car" might be a useful addition as well.

Welding the nuts won't make any difference as the thieves cut through the exhaust pipe. Although this is noisy, it is also very fast and they're gone before anyone notices.

welland · November 3, 2019

On 10/27/2019 at 12:39 PM, Britprius said:

You cannot do an emissions test on the Toyota/Lexus range of hybrids because the engine cannot be made to run continuously with throttle control "holding the revs at a given level" the engine may stop running at any time.

I've been wondering about this since I got my rx400h. Is there some kind of service mode which forces the engine to stay running, and also respond properly to the throttle control?

06_400_h_se · February 29, 2020

Hi, just to come back on this, the car went through the MOT without any issues. It's been running with the straight pipe now since October, with no noticeable change that I can detect.

ColinBarber · February 29, 2020

On 10/27/2019 at 11:24 AM, 06_400_h_se said:

This has stopped now since I've started putting the keys away in a shielded tin, so I guess this was a relay attack.

A relay attack isn't possible on a 400h, none of them came with smart entry. There must have been another reason.

unclepoo · February 29, 2020

Good to hear about your mot pass. I`m sure lots of owners of lexus and toyota hybrids will be happy to know there car can pass an mot.

Britprius · February 29, 2020

On 11/3/2019 at 11:19 PM, welland said:

I've been wondering about this since I got my rx400h. Is there some kind of service mode which forces the engine to stay running, and also respond properly to the throttle control?

You are correct about the service mode, and throttle response, but this still does not remove the MG1 generator load off the engine. The test requires that the engine is off load while doing emissions testing. Loading the engine increases the emissions above the fail threshold.

As far as passing the test with the cat deleted this is up to the examiner. If he does not realise a cat has been removed he will pass it. If he knows or suspects a cat has been removed he must fail it or risk loosing his MOT licence. He has the ability to check the cars specific specification via the VIN number, and if in doubt get advise from the ministry during the test.
The chances of the car being pulled for a roadside emissions check are remote to say the leased. More likely if you drive a commercial vehicle, but if you are stopped the ministry roadside testers they have all the details of the manufacturers fitments to hand down to specific VIN numbers as above, and have the ability to fine you, and remove your vehicle from the road until the system is re-instated if they can prove the exhaust emissions components have been tampered with. It is now an offence to tamper with emissions control equipment to override emissions levels.

I agree this is all a bit big brother or state control,but it is what it is. Gone are the days when we could make whatever repairs we wished to keep a vehicle running, and perhaps we are getting to the point where we should buy old vehicles that are exempt from controls. With no MOT requirement, no road tax, and cheap insurance motoring cost would tumble.

John.

06_400_h_se · February 29, 2020

John, do you have actual wording of the MOT testing section for exhaust emissions - is that publicly available? It would be interesting to see that. Technically the manifold cats are designed to remove the HC and CO, which I think is all that is tested on petrol vehicles. And the secondary cat would be to pick up residual NOX, of which there is very little on an RX in any case. I suspect even if it could be tested, it would pass HC and CO levels quite easily. But, I'd be interested to see what the wording is around modification, etc.

Colin, you're absolutely right, what was I thinking. I guess they mystery thief hasn't been in the area recently or they've give up on my car. My next step was to see if I can get the keys/transponder changed - presumably that would be the fix?

ColinBarber · February 29, 2020

8.2.1.2. Gaseous emissions

You must inspect vehicles with spark ignition engines first used on or after 1 August 1975.

You do not need to check:

L category vehicles
hybrid vehicles - with electric and combustion engines

https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/8-nuisance

ColinBarber · February 29, 2020

1 hour ago, 06_400_h_se said:

My next step was to see if I can get the keys/transponder changed - presumably that would be the fix?

It is very very unlikely that your key is cloned - that is hard to do.

It is possible that another key is programmed to your vehicle - a lost one else someone would have needed access to the vehicle with a master key to program in another one. In that case there is a way to delete all keys from the system and just add back the ones in your possession. Procedure varies on different Lexus vehicles but it should be available on a google search - normally you don't need Techstream or a dealer, there are button sequences to follow.

Jim Rausch · December 27, 2021

Hello. I need your help. My cat(s), at least the front one, was stolen while I was away for work out of state. The bandits cut the pipe in front of the muffler and cut the cat right at the exhaust manifold in the front. I have not see if they cut the rear one as I have been trying to find a diagram and the actual part numbers to replace the missing pieces. They also cut the o2 sensors wires which I understand there are 4 sensors. I am very upset this happen but I want to fix my 2007 RX400h to get it right. I have a mechanic friend willing to help as long as I get the right parts. Is there any ACTUAL diagrams available with the correct Lexus part numbers you can share or lead me to? I check with the dealer and was quoted around $4000 to repair the vehicle but my friend and I believe we can do the job together and save a ton of money. Any help would be greatly appreciated as my car sounds like a freight train going down the road and it is really really annoying, especially taking a lady out on a date!!! How emabarrasing!

Barry14UK · December 27, 2021

Let's assume an MOT fails the MOT due to absence of central cat. Wouldn't this then go on the cars record which means if car then tested elsewhere it would be an alert the the subsequent MOT tester to cause it to fail and any body else after that. Maybe best to find out in advance a garage that will not fail it!