sean_co

Are you talking about an additive to increase the octane a bit? Sent from my iPhone using Tapatalk

Hi Womble72 In the time I have had the F I have only used petrol from stations like BP/Caltex/Shell. Those are really the only places we can get petrol where I live. I only fill up with 95 octane, we have 2 options that's 93 and 95 even at the cost. I usually only fill up at one station I'll try a different brand but same octane, perhaps the brand made a change to their fuel. When your m3 had these flat spots were they always at the same rpm? Just to follow up on my previous post. I have cleaned the Maf and changed the air filter (now oem filter), it was dirty. Still have the flat spot at altitude but again I am visiting family at the cost and there is no flat spot down here. This is with the same fuel I filled up with at altitude. Will test again in a few days to be sure. Do these cars also have a map sensor? Sent from my iPhone using Tapatalk

Unfortunately i have not yet had it on the dyno, the one close to me is booked up to early Jan and want to charge a silly amount for a run. I went down to the coast for a funeral last weekend and down there it performed 100%. We live 1700M above sea level, strange that it ran 100% down there though. we are going down again in the next week so ill have to test some more :) while we wait for the dyno early jan i will check the fuel filter (in tank i believe), air filter and perhaps clean the MAF (which is new)

Thanks Stuno1 for the quick reply. i do agree that running standard headers with gutted primaries is not optimal by any means although its been running fine up till a month or two ago. i can't really put my finger on the beginning of this issue since i usually just cruise around. i will defiantly take up your suggestion and put it on the dyno to check that curve out. luckily I'm on leave today and there is one down the road from where i stay

Good evening all, hopefully someone here will be able to assist me in tracking down an issue. this recently started and is not 100% constant. under WOT through the gears there is a flat spot in power deliver from about 4600 rpm to about 4800 rpm, this becomes more noticeable in the higher gears but always between that rpm range. up to that rpm it pulls strong and the same beyond that rpm i have taken the car to Lexus to have it checked they told me they had it on the scanner on a test run and found all o2 readings were showing lean during that rpm range. they then tell me they can not trouble shoot further because of my decat and PPE engineering device. i dont agree with them that those are causing the lean condition since it only recently started doing this. unfortunately our dealerships here love to blame the decat for anything they cant find. i replaced the MAF and it feels better, not always holding back the power now but it does seem to happen after driving for some time. the one day this happened i also noticed a slightly longer than normal crank to start time, by longer im talking a sec or two more, nothing major but not usual. there are also no error codes as per Lexus and also no CEL. no cylinder miss fires in live or history. could this be a sign of a fuel tank pump going bad? the vehicle has the below changes 1) primary cats hallowed out (previous owner) 2) removed secondary cats (previous owner) 3) ppe sim (installed myself to fix the CEL from above 2 mods) 4) airfilter (installed because the garage said it was not done in the Lexus 90k service) - recently checked it and it is unfortunately aftermarket filter regards,

Thanks Stu if there is any good info i get i will post it here for the UK guys

have not checked on usa forums at this point. not an easy sound to pinpoint, is seems to be in the region of the high pressure pump will register on their site and see what they say about this.

https://www.youtube.com/watch?v=Tnibd6Av59Q https://www.youtube.com/watch?v=11p5ikcktjI i found these 2 videos on youtube. seems to exactly the same sound happening there.

unfortunately i dont have warranty left on this car. im sure in time i will either find the issue or find someone that can find it. i have just come back from an exhaust place, they listened and blipped the throttle a bit while listening and they saying its not coming from an exhaust leak they also saying it does not sound like tappets / lifters. i can believe that story from the lotus forum. you probably find the place quoting 10k knew all along it was just the filter and was going to pocket the rest of the cash.

so the dealership has had the car for 2 days now. they say they 99% sure is a leaking exhaust manifold gasket or cracked manifold causing that sound. only happens when its at operating temperature. in the same breath they say they saw carbon buildup in the cylinders (using a scope) and they need to strip the engine to find out what that is. 27 hours of labor quoted just for that. then a whole new exhaust system is needed also (because the back CAT were removed) to fix the sound im complaining about. i am completely loosing faith in Lexus. they complained about a "chip in the engine" also, that's the device from PPE keeping my CEL off. R21,000 to strip and check the engine and another R35,000 for the exhaust system. i have paid less for running vehicles before. it seems all these guys want to do is drop and strip the engine or replace things that are not even relevant. i would not be surprised if they quote an ECU just for good measure. im going to pick up my car from the dealership and take it to an exhaust place.

im saving this for the next plug service. looks easy enough to do. why are the dealerships saying they have to remove the intake for this job then? suppose just to make more money from us again

yes i have heard this. just recently i did this service. its such a silly design that the intake needs to come off to change the plugs. luckily the plug service is few and far between.

Good evening, i have a question about the ticking sound from the HP fuel pump. if you have good speakers / headphones you can hear the sound on this video link below. you can hear the so called normal sound on the left of the engine but the recording from the right side and under the car you can hear a different clicking sound. a more pronounced one. seems to go away when you bring the revs up to about 1500 ish and it cant be the timing chain or tentioner because its heard near the back or the engine, close to the firewall. https://youtu.be/DcQJbMCXK5A the dealership just says its the fuel pump but i dont think it is, does not sound like the usual ticking that the is250 has. does this sound normal?

nice quick reply :) well the camera was working but when i turned the steering wheel there were no guidance lines as normal. once i did the full left and right locks they came back as usual. very strange. so far things are ok again after the second reset, if it comes back tomorrow i will check the O2 cables. that should be ok though cause my scanner shows the O2 sensor passed and the CATs. haha, they passing now but dont even exist, O2 conditioner for the win :) been reading about zero point calibration, its resetting the steering wheel angle so the traction control knows whats happening. found it here http://www.lexusownersclub.co.uk/forum/topic/83148-gs300-2002-vsc-vsc-lights-on/ post number #3. would these pins be the same on the IS-F? perhaps after power loss the angles are set? i dont know there is so much electronic stuff going on in these cars

the O2 conditioner is working wonders. no more Cat error codes. infact no more issues / codes at all until today, i think i caused it though. i had the conditioner mounted outside of the ECU box, didnt look like it was going to fit properly. noticed it was getting fairly hot. no real airflow where i had it mounted. so today i moved it into the ECU box. tight fit but you can get it in there and its now running cooler then before. looks like there is an air vent into the ECU box. during the conditioner relocate i had the negative battery terminal off, just incase. was probably off for about 20 min. i noticed the first start after that the engine ran for about 3 sec and stopped, restarted and all was fine again except i got the VCS light after a few km. also noticed the reverse camera was saying initialising. went home and removed the negative terminal again for 5 - 10 min. on first start again it ran for about 3 sec and stopped, restarted and all was fine. camera did the same again so took a chance and turned the wheels full lock left and full lock right. as i did that the camera came right. am i starting the engine too soon after reconnecting the battery? seems like im starting it while its calibrating something or doing initial checks. no VCS light after this round, hopefully it wont come back. seems to be very fussy when batteries are disconnected. did a similar thing when i put a new battery in the car.

just 2 photos during the install. this was probably the most difficult wire to get to. on the ECU it is in port E3 28 which is right at the back, so the easiest way to get there was to disconnect the battery and unplug all cables. This brown wire and the switched power black/Red on port A6 2 were the only ones that i used electrical tape on as they were not cut, there were also soldered though. the rest of the joins were cut, soldered and heat shrinked. So far so good. went for a test drive and the DCT tests all passed. that includes O2 sensors and catalyst checks. no CEL currently and also no pending codes :hocus-pokus: .

today i managed to get off of work early and went through to an exhaust place. ironically they recognised the car as they were the ones that cut out the secondary cats. i wanted to check the primary cats so we put the car on the lifts and removed the exhaust from the primary cats. turns out they have been emptied out. its no wonder i keep getting the CEL, i am essentially running a cat less system. but looking at the car you would think the cats are there. long story short i have received my O2 conditioner and tomorrow morning i will be installing it. litle bit of wiring involved in some tricky spots by im sure this will clear the CEL for good. this is the start of the install, will post some more as there is progress tomorrow. will probably solder each connection just for good measure too, dont want intermittent connection issues

no new updates as yet. im trying to find someone with an IR thermometer. just want to check temps at the front of the cat vs temps at the back of the cat. that will give an indication of the cat condition. also before i replace anything i would like to check wiring from the 4 sensors just to make sure no one has tried to do something there. i did find one suspicious looking wire just loose in the engine bay, makes me wonder. i did dig a bit deeper into the diagnostic software and i found what looks like a slow O2 sensor warning so im leaning towards replacing them. but for now i just keep checking the error codes to make sure its nothing new. should have some time this weekend to poke around some more.

perhaps while im at it, might be a good idea just to do all 4 of them if the price is fair? for a minute lets assume all my O2 sensors are working. would this error then mean the primary (upstream) cats are faulty?

defiantly need the luck with this project. :) will see if i can get 2x primary O2's in the next couple of days. from under the car i was able to see the primary ones, how difficult is it to remove them? also if the primaries are faulty, would that not be messing with my Air fuel ratio?

Just a quick update. the air filter was replaced and air flow meter was cleaned (MAF). no longer getting lean errors which is great. fuel trims are very close to 0% most of the time now, both short and long terms. below is a screen print of the errors now. these are pending but they do set a fault after driving a few KMs'. i reset them and after some time they came back. as mentioned many times before these cars are ok with secondary decat, can this then be because of 2x faulty O2 sensors. should i be looking at the primary cat / O2 or the secondary cat (removed) / O2 with errors like this? better yet, what can i log to see which sensor is giving this error? i might try adding the "mini cats" back in just to see what effect it has on this error if any.

i agree with you, i think its something else other then the cats. with the OBD adaptor i checked the fuel trims and the short terms were fairly low but the long terms were +30%. started poking around and found a seriously dirty air filter and the mass air flow was all dirty. i replaced the filter and cleaned the MAF and the fuel trims have come down to a much better level. short term is around 2% and long term at idle is 0%. by the looks of things that must have sorted out the bank 1 and 2 lean error codes. as you say, if i get a CEL light again i will check the codes, most probably going to be a faulty / slow sensor. although now i do have a pending P0420 (catalyst system -efficiency below threshold), not sure if that will set a CEL over time? in south africa where i stay we can only get 95 fuel and at the coast i think we can get 98. no induction kit at this point in time, might be something to consider down the line once all the errors have been sorted.

Good evening, i was the one that started the topic http://www.lexusownersclub.co.uk/forum/topic/96535-exhaust-changes/. since it has moved from actual exhaust changes to trouble codes, i though i would start a new topic. been having CEL lights come and go, the last one in fact went away by itself. started up the car and code was gone. decided to get a BT ELM scanner and the torque pro app. past day or so things were fine. tonight i stopped at home and scanned for any faults and found P0171 and P0174 thats Bank 1 and 2 system too lean apparently. those codes are listed under pending fault and no CEL on the dash. I believe the ECU randomly sets a rich or lean condition to test the cats which have been removed in this case. would these errors be related to that or should i be logging other info / sensors to get a bigger picture of what could be wrong? been watching the short and long term trim levels and both short terms (bank 1 + 2) are between -7% and +7% depending how i drive but both long term trims are on +30% (seems a bit high)

Any CEL and VSC lights on your side? mine have come back unfortunately, but i have ordered an OBD2 adaptor so that should arrive on monday then at least i can see whats causing the issue. probably a faulty O2 sensor somewhere.

we do have a couple tuning shops here and indeed if i decide to replace the whole exhaust it defiantly will not be at the quoted agent print. i have paid less for whole cars that were just as fast, haha. :) i have no idea why they seem to think the engine needs to be removed to replace the 2 primary O2's. looks like a tight fits but makes not sense to have a whole engine removed to 2 sensors. Thanks Stuno1 for the advice, the email was removed on my post. although the vehicle maintenance plan is expired already so any repairs is up to the owner to pay. i did infact ask the tech why he says it will run lean (when i started poking around 8 days ago he mentioned it would run rich) and his answer was that my secondary O2's readings jump around between a lean reading and a rich reading, he says that "confuses" the ECU and it runs lean. at that point i didnt ask anything further because that is how an O2 sensor reads data, it flaps between its high and low readings. so to me it sounds like they working just fine. logically it makes no sense that an O2 sensor would give a nice stable reading as your exhaust gasses pulse, its not a constant exhaust stream.