Failed NCT emissions 2nd time help

mDx

Hello everyone, I own a lexus is200 04 and failed emmisions on nct 2nd time,
The tester sayed the numbers are changing rapidly and goes very hight and low again, he sayed labda is only 1 wich is Good it does the job and HC is 51 wich is very low and good aswell, its passing on low revs on 0.05% of 0.30 but high revs its 0.25% of 0.20% Don't please tell me to put **** into and clean whatever I know this cuz its done already. serviced regulary, could it be catalyc converter? Or something else? he sayed that the number i got is the lowes and couldnt go less but it does go higher than 0.25. Is200 doesnt have Maf sensor it has map sensor and dunno if it needs cleaning cheers for any advice given.

jimgoose

The first thing to do is scan for OBD-II fault codes. From your initial description is appears that the fuelling is swaying wildly between too lean and too rich, and there are a few things that could cause that, mostly sensor-related, e.g. MAP.

mDx

I don't think there is any fault codes as i did it recently.. however I did got once engine management light in bank 2 i think but I got it when the hole in the exhaust got big.
I removed it.

jimgoose

mDx wrote: »

I don't think there is any fault codes as i did it recently.. however I did got once engine management light in bank 2 i think but I got it when the hole in the exhaust got big.
I removed it.

OK, so it sounds like you had a lean-misfire due to a leak somewhere in the exhaust. Was that seen to and repaired properly?

mDx

Well if i had a leak my HC would be bigger tester sayed that he woudn't think about holes in the exhaust, hovewer i do have small holes but they are not leaking when its revd up only when the exhaust is blocked then it does leak but only a small bit.

wonski

I had a leak in the exhaust system twice and it was mentioned straight away during the NCT.

mDx

I am thinking of if I would have a leak in somewhere in the vacuum hoses? I can check that aswell. Maybe i have bad sensor
Should i check my MAP sensor for a voltage? Does anyone know what voltage should it give to ecu? i know that Co sensor should give to 0.9 - 0.3 V

mDx

Anymore conclusions of the problem.?

Mar4ix

what fuel consumption is ? As specified or it is higher ?

If there is no codes, i would put fuel cleaning stuff in fuel, go for good drive to make car warm up properly, and then drive as you stole it for good bit, high revs till red line. (needless to say that, oil , filters , sparkplugs, timingbelt (cant remember that car has chain or belt) be in fresh/good condition ) then after that pop in into garage who checks emissions, and see what it look like. wont be cheap to do tests ( id say 40 -50 quid ), but maybe worth it. even if then emissions is no good, go to dealers, see what they say.

I think that engine is just full of residues , same catalityc converter , it need give good blast. There was one crowd which was cleaning car engine internally with chemicals (cant recall name) , cost 150 ish if i am not mistaken, sure lads here was using them with various results.

mDx

Mar4ix wrote: »

what fuel consumption is ? As specified or it is higher ?

If there is no codes, i would put fuel cleaning stuff in fuel, go for good drive to make car warm up properly, and then drive as you stole it for good bit, high revs till red line. (needless to say that, oil , filters , sparkplugs, timingbelt (cant remember that car has chain or belt) be in fresh/good condition ) then after that pop in into garage who checks emissions, and see what it look like. wont be cheap to do tests ( id say 40 -50 quid ), but maybe worth it. even if then emissions is no good, go to dealers, see what they say.

I think that engine is just full of residues , same catalityc converter , it need give good blast. There was one crowd which was cleaning car engine internally with chemicals (cant recall name) , cost 150 ish if i am not mistaken, sure lads here was using them with various results.

All this that youve mentioned is done thats why its failed 2nd time, the inside of the engine is pretty clean, but I have a doubt about pre cats one of them i know is burned but nct tester sayed it woud say that, and probably still would pass. Plus yes I think it does run a bit rich, its is200 it takes alot of fuel afterall lol.

georgefalls

Have you checked the air intake flexi rubber hose..? Any small crack/hole will cause higher readings under acceleration.

mDx

its in place.

goz83

The Guy above is talking about a terra-clean. I would seal any holes. If small, use chemical steel. Give it a good run and pull up 10 minutes before your test, with the engine roaring hot. Turn the engine off the moment you park. Leaving it idle to keep warm is a sure way to fail emmisions.

JohnDx

:eek:2ND FAIL
TIME TO PUSH CAR OFF NEAREST CLIFF

mDx

goz83 wrote: »

The Guy above is talking about a terra-clean. I would seal any holes. If small, use chemical steel. Give it a good run and pull up 10 minutes before your test, with the engine roaring hot. Turn the engine off the moment you park. Leaving it idle to keep warm is a sure way to fail emmisions.

this way wont work as I sayed, the numbers are changing rapidly on the screen on emmisions.

flintash

its realy hard to say what exactly is causing the problem. did you check lexus0 forum, maybe u get an idea what is usually failing in your nexus. i had same nct failure last year. my case it was maf, but it also could have been lambda , cat. converter or just a leak in intake . its a ****y case for you this time. dont expect to find a firm answer here.

mDx

flintash wrote: »

its realy hard to say what exactly is causing the problem. did you check lexus0 forum, maybe u get an idea what is usually failing in your nexus. i had same nct failure last year. my case it was maf, but it also could have been lambda , cat. converter or just a leak in intake . its a ****y case for you this time. dont expect to find a firm answer here.

This is probably the best answer ive got so far, but the think is200 doesnt have maf sensor it does have map.

mDx

Okey so Ive pluged obd2 into PC checked the voltage of all sensors, and there is no engine light coming up even i reset ecu, Bank 1 sensor 2 didnt give low voltage no voltage for switch calculations, Bank 1 sensor 1 Ok bank 2 sensor 1 Ok so i think its after cat sensor, but does it makes my emmisions bad? I mean running rich? or its only indicated that my sensor is bad and cat is gone too. Cuz as I sayed before the light was coming up but i deleted and never ever came back on.

flintash

i used to get ecu light after longer journey in low revs.it said like fuel mix too lean??? just deleted and didnt pay attention until NCT. lol i cant recall exactly but i think the obd program was showing high LTFT values.that was my lead to the problem. i used like four apps and only one of it was really usefull. so try different apps. i had like 10 installed at the time.And I had all wiring diagrams and service manuals and then i was 1000% sure where is my MAF and all the rest sensors. there is a bit to learn if you going to solve the problem by yourself... or just get credit card and go to nearest motor factors.

flintash

deleted double post

mDx

Ill try to clean all sensors, and change the sensor 2

mossy50

a good lash of DIPETANE and drive the sh1te of it

ikeano29

mossy50 wrote: »

a good lash of DIPETANE and drive the sh1te of it

Be handy if you read the thread mossy before commenting

mDx

Om.. just bored and sick of listenning but some **** into and wreck it, I said it won't help. Did it already