ColinBarber

I'm not sure they could state the expansion ratio because 99% of people wouldn't know what an expansion ratio is or why it is different from the effective compression ratio. Why such a concern? Does it really matter? Technically the engine does have a compression ratio of 13:1 and at the end of the day running the Atkinson cycle improves efficiency by around 10% and the negatives associated are compensated by using a CVT transmission and additional power, when required, by the electric motors.

yes of course, sorry. Edited above.

Some people never use the parking brake, it seizes up and causes a MOT fail. If you don't engage it while the vehicle is moving the shoes will never wear out, the only potential issue is stretching or failing cables but that is extremely rare so it is always worth using it periodically just to keep it operating correctly.

It obviously stores any current faults, and it also stores freeze frame data - what the vehicle/engine was doing at the time of the fault occurring. Some faults will clear by themselves, the light will go out, however the ECU will still keep a record. It stores codes unless they are cleared by disconnecting the battery or using a code reader to clear them.

That part code is a space saver for the RC, I cannot see how it will fit the RC F. I suspect that site hasn't categorised things correctly. Brake pads too, the cheap ones come up as being for the RC and not the RC F so be careful if ordering from them. Cross check their parts codes with another site such as toyodiy.com

Not sure what Greenstuff are made from, I think Kevlar, but they are quite soft and therefore kind to the discs, but with quicker wear than OEM and possibly more dust. Redstuff are Kevlar with ceramic particles, they are fine with standard discs and supposedly reduce disc wear by half compared to OEM pads. It seems they sell both for the IS300h, but reds are probably recommended due to the weight of the vehicle (Green is more for hatchbacks). Here is their online shop - select pads as it will default to complete disc/pad kits. https://ebcbrakesdirect.com/automotive/lexus/is300h/2.5-hybrid-2013-/29626#prettyPhoto

Series IV GS all have the same mat design - just go with GS300h, you know then that is really is for the series IV because it didn't exist before then. Bootliners is where you need to be careful. The GS300 GS250/GS F have a larger boot, compared to the hybrids, so you need to get the right one.

If the fault remains that light will come back on again. For a hard fault it will come on straight away. If it is an intermittent fault or one that is related to Cat efficiency, it may take a while before light comes back on. If the light comes back on again and it is O2 sensor / emissions related then I'd say it would be safe to drive 100 miles to your preferred dealer.

and I don't think it is the shoes that are sticking, it is the pads.

Other than parking in a garage, the only really option is changing the brake pads to ones that aren't semi-metallic. Something like EBC Greenstuff or Redstuff pads. Take the car for a quick drive after washing it to dry off the brakes.

With the fault cleared they may not find any issue. Do you know what code it was? There are at least 10 different codes relating to the O2 sensors and emissions.

Yes, yes, and no. Just treat as normal.

Which cats, the pre-cats or main one?

I'd probably go with every 20k miles, and I'd start at 100k or 10 years.

On the Prius the static compression ratio is 13:1, effective compression ratio is 8:1 but the expansion ratio remains at 13:1. The IS will be similar. I believe the new UX250h will have an engine with a compression ratio of 14:1.

Hoping I can make it, if so it will be Saturday.

They have to be an approved fitter. But a 3rd party wouldn't invalidate your warranty, not unless a fault developed that was directly related to the install.

It is typically moisture at this time of year helping the pads corrode to the disks as they contain metal particles in the friction material. If the rotors have heavy corrosion on them then it will be worse. It will also be worse if you wash your car and then don't move it for a period of time.

Yes but Euro 6d regulations don't apply until 2021 so they have a bit of time. There is Euro 6d-temp that applies from Sept 2019 but the GS F/LC potentially could already pass that. I'm guessing the RC facelift forced a re-test (type approval as if it is a new vehicle) so Euro 6d-temp applies from Sept 2017, or Lexus don't want do more rework on the RC before 2021 so they made the change now.

It is DOHC. Lexus has never sold a vehicle in the UK without a DOHC head design.

Glad it is all sorted, and sounds like excellent service from Rockauto.

I'd recommend you remove the solenoid and check it is working, using a 12v battery and 10 W bulb in series. It is probably sticking or something is blocking it. I'd expect a P0753 if the issue was electrical, which is confirmed by the coil resistance being good.

That does look very dirty. I'd refill the pan, let it run for a bit and drain again to use up all of your 4l. You have around 8l of fluid in the transmission, ideally you want most of that refreshed. I'd recommend you do three drain/refills in total over the next few weeks.

www.toyodiy.com 17801-31110

I'm sure you didn't, just being clear to other readers that they shouldn't be going that low.