johnatg

No experience I'm afraid - my exhaust is still original and my car is 2006. Try this place: http://www.carpartgiant.co.uk/Products/Lexus/Is250/2.5L/Exhaust-Back-Box.aspx (Bottom one on the list of parts)

I'm not so sure - I think you should ask them to confirm that it will fit a 2009 - all the exhaust places quote different part numbers for pre and post 2008. If there are differences they won't be much, but it may mean making up adapters or cutting pieces off and reworking somewhere or other. The tailpipe shape never changed - all the tailpipes from the silencers are round (and quite large diameter) but have what Lexus describe as 'tail exhaust pipe baffle sub-assembly' pushed on to the end - (exhaust trims to most people). Those are polished stainless steel and oval shape - they all look the same to me, although no doubt many have been replaced. They get in a mess, but with a bit of TLC you can restore them to more or less original condition - they are made of good quality (if a bit thin) stainless steel. The originals cost upwards of £50 but you can get universal replacement trims for a tenner or so.

There we are, sir - just like new! Yeah, right.......

Here's a diagram of the IS250 fuel system:

Connect to the vehicle, choose the appropriate model, year etc, then go on to System Select, click on 'engine' then 'Trouble Codes'. You can only find out what does what when it's connected to the car. Check out the 'help' section in the program - it's really quite helpful!

Yes - and also the timebase. I've looked at the Techstream 'Help' section - if you look under 'Diagnostics functions....'/'Graph function (data monitor)' - scroll down to Menu - Time setup, it shows you how to adjust the horizontal axis to show the data over different time periods. And a whole lot of other settings as well. Not tried it live, just on my desktop so far. Must really spend some time with Techstream - it obviously can do way more than I thought - or at least have tried so far!

The first problem you need to solve is the misfiring - I assume those codes are still returning if you clear them? If you manage to restore, or replace, the cats they will just be poisoned again by the unburnt fuel from the misfire. I don't think there's a code as such for failed cat - you'll just get a code for lambda being out of range. Odd that you don't seem to have that but Techstream will show the lambda readings from the downstream oxygen sensors. Get hold of Techstream - that will show which cylinders are misfiring and to what extent - see this pic: That screen shows no misfires, but during the half hour or so that I was running the engine to take that and other shots, one or two misfires did show up later. It is also a little concerning that you are smelling rotten eggs inside the car. It is true that you can smell Hydrogen Sulfide in very small concentrations (it is detectable at less than 1 part per billion) but it does imply that exhaust gas is getting into the car. Check for any leaks - eg trunk seals and try differnt heater settings (fresh air/ recirculate, fan speeds). Keep the windows shut. Try using different fuel - some gas contains more sulfur than others - the Bakken deposits are rumoured to have particularly high levels of sulfur - maybe your gas is coming from there? But that would be affecting everyone and there's no evidence of that. Hydrogen Sulfide is extremely dangerous - you should not drive long distances if you can smell it strongly. And one of its effects is to deaden your sense of smell, so you smell it less as time goes by.

They do - but mention numerous other factors too. Now I have virtually zero knowledge of, and am certainly no fan of, modern diesels - I did run a Citroen BX19 diesel estate back in the mid 80s - that was a brilliant car for its time, but as it was a company lease I never got to grips with the mechanics. So anything I say here is pure hearsay from the article and I only raised the topic because of the frequent er..discussions about the subject here. The technical adviser for the article was the founder of DPF-Doctor, an organisation which is apparently establishing a nationwide chain of garages equipped to deal with the problems. They advise that frequent causes are people ignoring apparently minor warnings and malfunctions - general maintenance, really. But anyone with, or anticipating problems really should buy the mag (£4 for one off) and read the whole thing for yourselves! The front cover is emblazoned 'Troubleshooting Diesel Particle Filters'!

They're very much on their last legs - collection in store only (and they're not taking cash - card payment only)

Another quick heads up! If you need a leather cleaner/protection kit - as you may know, Multiyork (furniture retailer) are in administration and their stores are having a sell off. I bought a leather care kit (250ml cleaner and 250ml Protection cream) for £3 - reduced from £18. It may or may not be the best on the market, but for £3 who's complaining? You probably only have days left to snap up a bargain!

Just a quick heads up for those of you with diesels - Car Mechanics magazine this month (February 2018 issue) has an interesting article about DPFs - how they work, what goes wrong and how they can be cleaned etc. It also mentions EGRs etc (and Catalytic Converters for petrol engines) but the main focus is on DPFs

Yes - I'm sure the wideband sensors run at about 3.3V with a stoichometric mixture. The older type downstream sensors vary between about 0.1 and 0.9 volts but Techstream just reports lambda, which we discussed somewhere above. To get the graphs you click on whichever parameters you want on the top 3 screens above. The particular row is then highlighted blue. Then you click on the graph icon at the bottom of those screens. You get the parameters shown as stacked graphs (4th pic down). You can then choose to show any one of them full screen - there are menu, full screen and graph type buttons on each graph. I guess there's a way of setting the timebase but I haven't explored that.

In the interests of science, I've been out and played with my Techstream a bit - and surprised myself. Here are a few snaps of live engine data, concentrating on the oxygen sensors (upstream and downstream). The engine was cold when I started (see it says 5 deg C somewhere) and warmed up whilst I was taking the pics and working out what I wanted to show. Don't worry James - by the time you've got the Techstream connected and worked out what's what with the program the engine will be nicely warmed up if you connect the Techstream as soon as you get in the car and start the engine! Note that the upstream sensors read about 3.3v and the downstream ones show lambda about 1.000. Pay no attention to the numbers - I just chose the pics at random from the ones I took, then cropped and resized them. The numbers are just to differentiate them as I saved them.

To an extent yes - It's a while since I've hooked up my Techstream - I think it's quite hard to get the actual voltages read because it kind of lags what the engine is doing dynamically. The Workshop manual never seems to refer to using Techstream - they do everything with the Intelligent Tester. But Lexus and Toyota dealers do use Techstream but I think only for setting equipment options and things like that. It's handy to drive with Techstream connected up, but for heaven's sake get someone else to read what the computer screen is saying whilst you're driving!

The 'tester' referred to in the manual page is not Techstream - it's a hand held hardware device - known as an 'Intelligent Tester', which Lexus dealers have. You can buy them but they cost about £300 AIR. You can't do any of this testing with Techstream, but it does give you live engine data on fuel trims etc.

Hmm...hard to diagnose anything from that - except that you are in USA? Do you have an annual emissions check - if so, what did that say? I think you need someone who can use an oscilloscope to diagnose where your misfire is and what is causing it. No point in trying to replace anything else or tackle the smell until that has been sorted out. It is just possible, although unlikely, that you have an internal engine problem - burned valve or broken piston ring so a compression test might be a good idea.

The codes indicate engine misfires. That comes down to plugs, coils or wiring. Odd that they're associated with rotten eggs smell and indeed that is usually a cat problem. Possibly the cats have been damaged with excess fuel (ie unburnt fuel from the misfiring cylinder(s)) What petrol do you use? Not supermarket fuel, I hope. Try using Shell V-power. Was there some sort of fuelling event just before this all started?

Here are two hopefully useful diagrams. One is the circuit diagram - you will find the two 15A fuses three quarters of the way across, next to the blue boxes representing the headlamps. The other is a location diagram, showing the location, in particular, of Engine Room no 2 R/B, within which the two fuses in question are located. HL.pdf 2018-01-14_165234.pdf

The 30A fuse is a main feeder to loads of things. The two 15A fuses are individual to each low beam headlamp. Sent from my PSP7551DUO using Tapatalk

Remove the left side inner wing cover - you'll find the type B fuse box under it. Sent from my PSP7551DUO using Tapatalk

Doesn't your car also have the Type B fuse box - a large squarish one just behind the left side headlight? In there are two 15A fuses in positions 12 and 13 which also feed the headlights (the right side is no 12). I think you will find that has blown. See pages 274 and 308 in the Owners Manual (if the you have the same edition as mine)

The box print says O2 Sensor - search on Google for 'Translate to Japanese' - first result is a box - you put the english (ie sensor) on the left and the japanese appears on the right - exactly the same as the box. You don't need to translate O2 - element symbols and numbers are the same in english and japanese! That doesn't mean it's genuine of course! I'm wondering - could these be downstream sensors, rather than upstream? Presumeably the screw fitting is the same - are the electrical plugs the same?

There's a bit of faulty geometry on IS models at full lock - Ie the geometry isn't quite to Ackerman rules which mean the wheels should follow parallel arcs when the wheel is turned - or not quite in the case of IS. It only affects full lock (or near) positions and often the tyres iron it out. Sometimes you feel it as a single knock or a series of knocks as the tyre slips on the road. And it can depend on whether you were moving forward (or backward) when you were turning the steering wheel - you always should be moving as it greatly reduces stress and wear on the inner and outer track rod joints and the steering rack. Nothing to worry about.

Yes the big oval things are the silencers. I'm not sure what Lexus use. There are two common methods - one is where the panels are simply bolted to the floor - the bolts screw into tapped holes or captive nuts. This is probably what Lexus use. The other method is where there are plain studs protruding from the floor and the panels are held to them with starlock washers. The panels have probably corroded around the fixing holes, so now you have big holes with rusty edges. You can usually effect a repair by using repair washers - they are about 3cm in diameter with a 6mm hole. That will cover the damage. Or you can make up a cross with perforated strip (perforstrip is one brand - accessory shops sell it or other brands) as big as required to extend beyond the damaged area. You may need new bolts and the repair washers as the holes in the perforated strip are quite big. You will probably need new starlock washers as they often break when you prise them off the studs.

No - it won't make any difference - except that you'll be able to get underneath - warning - DO NOT RELY ON JUST THE JACK - USE AXLE STANDS OR SIMILAR. You may be able to work around the silencer, or you may need to remove the silencer.