johnatg

Thanks Ken - makes things clearer..

I'm completely befuddled now. The exhaust has four components - two manifolds (containing a cat each), a front section (also containing two cats and a resonator) and a tail section (which includes two back boxes). Thinking about Mo's picture - the only joint with a cat close to it is the one between the manifold and the front section, but the front cat is forward of the joint, whereas the pic is labelled with a cat behind. The rear cats (in the front section) are way back and nowhere near a joint. Mo talks about two joints/gaskets - which must be the ones between the manifolds and front section. the manual doesn't show springs on the bolts of those joints. The single joint between the front section and tail section does have springs - it has the resonator close in front of it and nothing but the Y joint and back boxes behind. So - Mo - which joint is your pic?. Ken - what do you mean by 'cat back' and middle section? Is it front cats back - ie manifolds back (ie front section and tail section and therefore including two rear cats and the resonator)) or just the tail section including two back boxes? What does £3500 get you - a front section and tail section or including manifolds (but you say manifolds back)? I can't understand the difference between cat back and manifold back (as the cats are included in the manifolds). Which part exactly did PowerFlow do for £700? (My car is 2006 and still on original exhaust so I'm thinking all this might be relevant sometime soon!)

Sorry - I see you saw the gasket. There are two joints and gaskets at the front of the centre section. Sent from my PSP7551DUO using Tapatalk

No - there's a gasket - it will be mesh/composite sort of thing. I'm surprised it has deteriorated. The green arrow points exactly to it. I think we are talking about the joint in front of the centre section, not the one behind it as per your pic. Sent from my PSP7551DUO using Tapatalk

Nothing there looks too bad. No damage to the pipes? I would have thought that those nuts/bolts would undo with a good soaking with Plus Gas. Or cut the bolts - not sure if there's a spacer between the flanges, but that's easy enough to replace

Hmm...maybe a bit more damage than I had envisaged. Beware of spending too much on patching up a disintegrating exhaust - such repairs rarely last more than a few months at best. Better to spend some money on replacement - but the centre section is expensive, even to get fabricated - I assume it is the centre section and not the manifolds where the damage is? (The manifolds are the pieces directly ahead of the joints you describe - they also contain a cat each.)

Why cut the pipes and weld? Why not just cut the nuts and bolts off with an angle grinder or hacksaw, replace the gaskets and use new (preferably stainless) nuts and bolts? (I don't think that they are captive studs - just normal nuts and bolts) That would take a lot less than two hours and be altogether a lot less effort - and a better job!

That (~14K miles) is about what I got from my last rear pads - EBC Ultimax. I've replaced them with EBC Redstuff (I use Redstuff on the front - they produce very little dust and what does get deposited wipes away easily as Redstuff contain no metal - they are ceramic - the only pads which don't deposit metal particles which eat into the paint/lacquer of the wheels). They are a bit expensive though. But worth it for their excellent braking and fade resistance (once they are bedded in). I once posted that I was going to use Yellowstuff at my (then) next pad change, but then I found that they contain metal. As I said, Redstuff are the only ones (of any make) that don't

See attached pdf for troubleshooting. Height control.pdf

I very much doubt that it's skimping. I suspect that feeding the exhausts into one pipe smooths out the pressure variations - there are 3 pressure peaks per engine rev and the peaks from each bank will be out of phase with each other. So by feeding the peak from one bank into the dip of the other, you will end up with a smoother overall pressure wave and hence less noise. But then why separate out into two pipes and two silencers - was that for aesthetics or does feeding your smoothed out wave into two pipes and silencers make the wave less energetic still and therefore make it quieter? I think the latter.

Certainly not. The original is nicely flared with a proper Y joint. As for making more noise...hmmm....swap it for a Civic Type R? 🙂 (And I speak as someone who also drives a supercharged MX-5 with a Jackson Racing exhaust - and that's about as antisocial as you can get!) Horses for courses!

That's the 'snow' button /switch - S is the gearstick position - PRNDS!

Hard to say - I think it's all gearing, but it seems to hold the gears longer - ie use higher revs - in S mode. But as Paul said, you can use the PWR button / switch for more power. Both S and PWR make for less smooth progress, although S is good for country roads with lots of low gear corners - cuts the number of gear changes which actually smooths things a bit. Sent from my PSP7551DUO using Tapatalk

'When the car was in Sport, the gear indicator number on the dash just read "4" and didn't change with the gears as it did when the car was in Drive. Is this normal?' The gear indicator on the actual dash panel shows the highest gear available when in S mode. You can change that, up or down, with the paddles. When you switch to S mode, it automatically selects 4. On older cars like this, the paddles only work in S mode. It still works as an auto - just on the lower 4 gears. Paddle up and you get the range 1-5 or 1-6. Paddle down and you get the range 1-3 or 1-2. etc. I keep the current gear showing in the information panel at the top of the dash - you select that with the display button on the steering wheel - it cycles through various things like outside temp and fuel consumption - and current gear engaged.. Once you get used to it, you can drive like a manual - select 2 as your max when you take off, up to max revs, paddle to 3, max revs, paddle 4 etc. By now you're well over the speed limit. All that is if you want to drive like a boy racer. It's fun, though! It can be useful to switch to S and paddle down to 3 (or even 2) on steep hills etc. That helps with engine braking.

You can delete the 'technically'! Keep the halogen bulbs handy!

Have you asked? If you have a fault and a warranty you might have a good case for getting it fixed!

Don't know if this helps - there are 4 of these diagrams - this is just one of them and I think is the most relevant - I think you're looking for item P1. It is located behind where I think your pics show you have dismantled. The other files have the same diagram but reference different parts of it. They show why IS250 electrics are such a nightmare! There are another 4 diagrams showing the wiring in the body (as opposed to the instrument panel) InpaneR-P4.pdf

I suppose that IS250s don't really have a throttle position sensor as such - one understands that would be a sensor in the throttle body, measuring the position of the butterfly. The IS250 has a motor in the throttle body, driven by the ecu and acting on input from the switch, or 'sensor', on the accelerator pedal - as per diagram. If there was no connection at either the pedal or throttle body I guess the engine would remain at idle and you wouldn't be going anywhere very quickly!

It's integrated into the throttle body - not accessible as a separate item. See pics for location and inspection. Further tests involve the Intelligent Tester - a hand-held piece of kit which plugs in to the OBD11 port.

Here is part of the circuit diagram for the clearance sonar system, along with parts location diagrams. Lexus seem to regard Clearance Sonar and Parking Assist as two distinct parts of an overall Parking Assist/Monitor system There is an extra part of the circuit diagram when the sonar system is linked to the parking assist functions, but I don't think that applies to Paul's and my cars. There are lots of pages of the workshop manual dealing with trouble shooting and testing and settings, but they all require the Intelligent Tester - that's a bit of kit which dealers have which is used for all sorts of things. It is not the same as TechStream which I don't think will help here. Intelligent Testers come up for sale occasionally, but they cost about £300.

That's right. Incidentally they don't work when covered in snow and ice. Sent from my PSP7551DUO using Tapatalk

Apologies - just something you wrote once! SportContact6 are no doubt brilliant (and expensive) but AFAIK they are only available in 19-23". For most cars PremiumContact6 replaced both PremiumContact5 and SportContact5. Unsprung weight is a key factor in handling - I was surprised that it made a big difference to ride as well. Sent from my PSP7551DUO using Tapatalk

I recently fitted these - 17" Konig Ultraform Gloss Graphite from Wheelbase, fitted with Continental PremiumContact 6 tyres. I chose the wider rear wheel option but Wheelbase rang me and suggested they send 4 wheels same width (ie 8J) as the wider rear ones sit too far outside the wheel arch. They did, however supply wider rear tyres (245). This combination isn't actually offered on the website - you could get 245 with 9J wheels or 225 tyres all round with 8J wheels. But I ended up with 225 front and 245 rear on 8J. (Don't bother to criticize, Linas - I know you don't like Continental tyres). 🙂 They are brilliant - substantially lighter than the originals - they have vastly improved the ride (I suspect down to wheel weight) and steering sharpness (I think due to the tyres and the slightly wider track - they sit slightly nearer the outside edge of the wheel arch - slightly smaller offset than standard). Somewhat understated in appearance I know, but they somehow make the car look more aggressive without being in your face. I love 'em!

Not so fast - mine has the parking sensors at the rear - not at the front - but it doesn't have a light on the dash to say parking assist is working, it doesn't show up on the multi-information display, it doesn't show up on the satellite switch settings (only speed and tach are there) and it doesn't beep when selecting reverse. But it does beep (progressively faster) when you reverse up to an object. I can't just think of what Ian can check, but don't give up yet!

The body ecu (which is the body control module) has the OBD11 plug as part of it (in the bottom), if that helps to locate it.