GrahamG

Hello Vick and Merry Christmas, Father Christmas might tell you that the codes were caused by the ECU being confused by the low battery. Failing that just one code is relevant and the others have been tripped by the interconnectedness of all the electronic complexity. My Walt Disney story ends with your expert independent garage clearing the codes [after carefully taking note of them] and you drive the car with the new battery and they never come on again. Well it is Christmas eve. Sorry I am not the expert you need but let me wish all the best to your father.

I am the original poster and can report the low tyre pressure warning and the red triangle exclamation mark have both disappeared without any remedial action. A new lambda sensor has just been fitted which appears to have corrected a lumpy idle and presumably Lexus Guildford cleared the codes from the ECU. Whatever happened the car was returned to me without the tyre warnings. My criticism of lexus design is that the warning for low pressure should be amber and not red. On the motorway in road works my wife seeing the red triangle [but not the text reading low pressure] dived through the cones into the works area thinking the car was in meltdown. There was a nail in a tyre but the journey could have continued safely for some distance. Glad I was not on board because it must have been quite hairy. More recently the warning came on again on the same motorway and amongst the same road works but this time there was no problem with the tyres or their pressures.

The problem had been occurring after 25min driving and the driver who delivered the car home to me confirmed there was no misfire after a 35min trip. So no guarantee now but I live in hope.

Thanks for everyone's contribution. Lexus Guildford were reluctant to fit a new Lamda sensor because they could not guarantee it was the problem but after waiting over an hour for a diagnosis I gave the go ahead and took a taxi home. Next day they delivered the car home to me [35min] for £360 total, car cleaned inside and out. Interesting they charged £135 plus VAT for 1.5 hours labour [ actual time, at least 2.5 hours] an hourly rate therefore £108 inc VAT.

Thanks for the suggestions. Have the car into Lexus Guildford next Thursday for a Techstream code analysis. It has only occurred when engine warm. Car starts perfectly. Will report findings then. Very strange to me how it can be so bad at just one set of traffic lights and then disappear for months on end.

Just connected an OBD scanner and just one pending code PO133 which points to a faulty O2 sensor and a number of other possible causes. If you know these causes does any fit with the intermittent nature of my problem? Two years ago this happened to me at the lights, so bad I thought the engine would stall but it pulled away and for a year no repeat. In the last few months it has happened three times with increasing frequency.

Can anyone offer some possible causes of an intermittent rough idle? It is very rough, possibly half the cylinders out. On most journeys there is no problem. When it occurs there is missing as the car accelerates away from stationary up to about 15mph and then it clears and all is smooth. In a car park today it cleared up as I played with P, N and D. I returned after an hour and drove home normally. At speed acceleration is smooth and powerful. Car is fully Lexus serviced with 88,000 miles. There are no warning lights on dash. I am asking for a list of possible suspects because the intermittent nature of the fault may be difficult for a garage to diagnose.

I may not be a great help here but I have definitely read on the USA owner's website of original Lexus foam seat bases being bought and fitted by upholsters. Cannot recall the cost of the foam part but it was original equipment and did not strike me as exorbitant though not cheap. The owners discussing this matter were most concerned about how to improve on the original seat. It might be available on Rockauto.

Just read on the USA owners club site that Rockauto are now stocking the Arnott after market air struts for the rear as well as the front. $608 each for the rear and $415 each the front.

On the USA club site there have been a couple of owners who have gone back to the LS430 after experiencing a LS460 but that by no means represents a universal opinion. If you decide on a LS430 then you might want to hold out for a facelift version, '04 to '06.

Had been running at 33psi and then tried in vain 36psi [measured cold]. See little point going higher for my low speed and low load driving. There is a Youtube video of someone changing over a second hand ABS controller on a Toyota Camry and it is very straightforward. Unfortunately on my Ls430 the controller is jammed against the bulkhead and a changeover would include the whole pump unit with its pressure pipe connections to each wheel, master cylinder etc, which is beyond my ability. A pity because complete units can be had for about £200 on Ebay.

Tried some extra pressure in the tyres but still the warnings come on. Google confirms the light on is not a MOT fail for a 2004 car. I now have a piece of black tape over the red triangle and will live with £2500 in my pocket. Will ask Paul Frost how much he wants for a scrap ABS actuator but it is bound to be too much.

Thanks John, I hoped it would not be a fail for cars built before TPMS was mandatory.

No, all four tyres are not matching. A pair on both front and back axle. It has been like that for two years without problem. All in good condition with plenty of tread, 5mm back pair and 6mm on front. Bridgestones and Avons.

Yes Sean you are right. Should have driven the car for 20 minutes after the reset according to Lexus Guildford though nothing in the manual about that. Problem is now cannot get it to reset. Will try a few more psi in each tyre. If it is a faulty ABS actuator then that will be £2,500. Guildford see about one a year of the 250 cars they service. Will check with a MOT inspector if the light on is a fail.

After a spell of high speed driving I am getting the low tyre warning. When I clear the message by holding the appropriate button for 3 seconds the warning [written warning and red warning triangle] disappears and stays off for low speed driving. It is almost as if it is detecting 'high pressure' because it comes on again after a sustained period of high speed driving when the tyres have warmed up. Needless to say the pressure in all four tyres is as it should be. My system measures the roundness of the wheels and does not have the more modern pressure transponders in the wheels. Any advice on how to sort this false alarm.

Switch off AFS when go abroad, ie when you drive on the right.

I have the Avon ZZ5s and I am particular about quiet tyres. Will be buying them again.

Perhaps ask your local Lexus main agents who they use.

I wonder if it might not be possible to arrange special insurance through a broker to cover the extra loss in such a case. If you could show the bill for the paint work you would have a legitimate financial interest that should be insurable. Just a thought.

The price would be appropriate for a Lexus main agent, in my opinion.

You deserved better than that from a 40k tranny. All of us following your process wanted to see success.

Like you Phil I have been concerned about possible failure of an air strut and have concluded the way to go is to replace with the Lexus 'metal' suspension. Our Ls430s were offered with both air and traditional shock absorbers so to use Lexus components would guarantee an original ride and overcome any problem with insurance. Unfortunately pricing up the parts in the UK comes to about £2,200 for 4 corners but if obtained from the US could hopefully reduce cost and I have been hoping someone here would try this solution which is well documented in the US owner's club site. The pricing there comes to the cost of all four in metal for one air strut. The labour is not a lot.

Shows how discerning was the selection process if they chose someone who was only there because his mum sent him. I have read many biographies of the great and the good and one quality they all had in common was perseverance. What some men have overcome to be successful is mind blowing including among business men multiple bankruptcies. It is determination that separates the wheat from the chaff.

You made it to the final round. You must have been doing a lot right.