205 Gti6 Mot....

[BuD 0]

For what seems like forever I have been plodding on with my 205 gti6 and last week I took it for the MOT.

 

It sailed through everything apart from failing the CO aspect of the (non cat) emmisions test.

 

CO: 5.84% (allowed 3.5%)

HC: 268 (allowed 1200)

 

Am really busy with work atm so took the car to peugeot dealers and asked them what was up with the emmisions. They came back to me that everything was fine and it was the lack of a cat causing the problem!

 

So my questions (please, please reply if you can I have 10 days to restest and tax or it will be a full retest and SORN)

 

1) what CO readings do you get for your non cat gti6 engine - can it pass the test?

2) (presuming yes to question 1) what do you think could cause my high CO reading (car drives fine, no engine management light).

 

Car details: des exhaust - no cat, original management and ecu, engine totally standard apart from K&N style air filter and carbon canister removed, sensor left unplugged.

 

Am planning to do a decent write up for the "car works" forum but heres a pic of the engine bay.

 

 

Help!!

[ablister 31]

i'd say a cat would cure that too but they are expensive (well, good ones are).

 

I mot'd a 407 2.2 dw petrol the other day which failed on similar readings which was down to a faulty cat. The annoying thing is that car drives 100% perfect, just emisions were sky high

[welshpug 1,657]

sounds like a lambda/ecu coolant temp sensor fault

[jackherer 543]

Do you have the lambda probe fitted in your exhaust?

 

There is no way you need a cat to pass a non-cat test, if your lambda is OK check the spark plugs and coil packs.

[Jon_Bmw 13]

If you want to fudge it through so you can get it on the road, increase the idle speed slightly and cause a slight vaccum leak after the AFM. Then it gives you a little more time to sort it out if you are in desperate need to get it done(free retest perhaps?)

[tidypug 5 2 Cars]

My car failed its mot for exactly the same reason. I changed the lambda, tried again, still failed on emissions. When i asked the tester if he had put it through for a test with a cat he said "yes" . He then put it through for a car without and cat which it then sailed through.

 

So double check that its been put through for the right test!

[welshpug 1,657]

from the stats quoted I would say that its a standard Emissions test for a 205, i.e there's no Lambda value given, and the CO limit is far greater than a CAT test.

 

here's a VERY useful link which you can use to check your ECU coolant temp sender, (the green one) http://www.306gti6.com/forum/showthread.ph...0340&page=1

 

edit, no data there for the Lambda, unsure how you'd test that one, though I "think" its pretty similar to testing most sensors, sure someone will assist there.

Edited September 30, 2008 by welshpug

[mojo1997 0]

my GTI-6 306 failed MOT last week on emissions similar to yours, changed the Coolant Temperature Sensor (£12 from GSF) and it passed.

[Alastairh 47]

Out of intrest if you've been using the car up until now. What sorta MPG / miles to the tank have you been getting, and what gear box are you running?

 

Al

Edited September 30, 2008 by Alastairh

[BuD 0]

sounds like a lambda/ecu coolant temp sensor fault

 

From reading the forums this what i thought - and from the replies still do.

 

 

Do you have the lambda probe fitted in your exhaust?

 

Yeah have the lambda fitted, plugs are new and no hesitation when driving but good advice - may have to look at ignition if lambda\cts draws a blank.

 

There is no way you need a cat to pass a non-cat test, if your lambda is OK check the spark plugs and coil packs.

 

This is what I thought - "surely not every 205 gti6 on here has had to fudge the mot" - although I was begining to question it!

 

If you want to fudge it through so you can get it on the road, increase the idle speed slightly and cause a slight vaccum leak after the AFM. Then it gives you a little more time to sort it out if you are in desperate need to get it done(free retest perhaps?)

 

hehe sneaky - i like it!! - although I cant change the idle, I may have to try introducing an air leak but am hopeful of a proper fix.

 

 

My car failed its mot for exactly the same reason. I changed the lambda, tried again, still failed on emissions. When i asked the tester if he had put it through for a test with a cat he said "yes" . He then put it through for a car without and cat which it then sailed through.

 

So double check that its been put through for the right test!

 

 

Defo the right test - read your post about the wrong one before hand so explained to the tester, he said he wouldnt have even contemplated the cat test for a H plate!

 

from the stats quoted I would say that its a standard Emissions test for a 205, i.e there's no Lambda value given, and the CO limit is far greater than a CAT test.

 

here's a VERY useful link which you can use to check your ECU coolant temp sender, (the green one) http://www.306gti6.com/forum/showthread.ph...0340&page=1

 

edit, no data there for the Lambda, unsure how you'd test that one, though I "think" its pretty similar to testing most sensors, sure someone will assist there.

 

Thats right it was definitly the right (non cat) test. Will be testing the CTS tommorow. According to my engine management book you need a scope or at the least a mm with max and min function (neither of which I have) also getting the test probes onto the pins with the car running is easier said than done!

 

my GTI-6 306 failed MOT last week on emissions similar to yours, changed the Coolant Temperature Sensor (£12 from GSF) and it passed.

 

Good tip - will be testing this with multimeter tommorow.

 

 

Out of intrest if you've been using the car up until now. What sorta MPG / miles to the tank have you been getting, and what gear box are you running?

 

Al

 

No have not been running it - box is Mi16, but I have ran a 306gti6 for 40k 2 trackdays + nurburgring tho. 270 - 300 miles spirited A road driving (from £60 tank of 98ron) My girlfriend managed nearly 360 miles but I cant resist the hi rpms enough.

 

 

 

 

Cheers all for the input - anyone who has MOT'd a 205 gti6 would love to hear your emmisions results.

 

Will test CTS tommorow and probably take lambda sensor off the 306 and try to get an emisions test done. Will definitly keep this topic up to date with progress. I feel a lot more confident now that I wont have to spend more cash on a cat exhaust just for MOT day!

[jackherer 543]

hehe sneaky - i like it!! - although I cant change the idle, I may have to try introducing an air leak but am hopeful of a proper fix.

 

An air leak only makes a difference if you have an AFM, as the GTI6 has a map sensor it wont make any difference.

[Jon_Bmw 13]

My bad as its still an mi16 I assumed they were still flap based.

[BuD 0]

Quick update: CTS tests fine and compares well to my 306 one. Lambda would not come out of the cat on the 306 so have taken the plunge and ordered a new one. Fingures crossed this fixes the problem.

[pug_ham 244 3 Cars]

Bud, have you got the K light connected up & working? If the lambda was at fault then the K light would be on intermittently at least imo.

 

You can test the lambda oxygen sensor by measuring across two terminals on the lamdba plug (1 & 2, pin 1 is top pin with the master key on the plug to the right). You are looking for a 20ohm max resistance.

 

I tested the lambda on my mums 205 auto when it wouldn't pass the emissions this way & it was dead. I was advised to make sure I got a genuine Bosch lambda & not a universal one so I did (only £45) & it sailed through afterwards & passed again this time round. The garage had already changed the CTS but to no avail dropping the emissions to under the limit.

 

GRaham.

[BuD 0]

k-light is connected but doesnt show any errors, nor have any been logged by the ecu - will test the sensor I have tommorow (Friday).

 

Have already ordered a new one from peugeot - have paid top dollar for it but like you say it needs to be a good one and I couldnt be bothered to muck about so just ordered it...

 

Will be worth it if it fixes it.

 

Interesting about the testing the sensor - I must admit I didnt think a resistance type test was possible - I thought the wave form needed to be obsevered while the car was running (even this requires a break out loom)!

 

Will report findings - thanks again.

 

EDIT: what would your thoughts for causes of high CO be on GTi6 Graham if CTS and o2 sensors prove fine?

Edited October 2, 2008 by BuD

[pug_ham 244 3 Cars]

There are two tests for the Lambda listed in Autodata, one for the heated o2 sensor & the other which I posted above for the oxygen sensor.

 

The other test requires access to the pins in the plug with it still connected to measure the voltage across the sensor iirc on pins 3 & 4.

 

I think I only paid about £10 more for the proper NGK lambda for my mums car than I'd have paid for a universal one so it was well worth it as this year it sailed through the emissions well under all its limits.

 

Graham.

[BuD 0]

Ah i see!

 

The one on the gti6 is a 4 wire type which (I think) is heated - I dont know if this means your test is unviable or not?

 

In brief my haynes ecu manual says:

 

OS heater wire: should show battery voltage.

OS signal: should be 0.2 to 1.0 V (1.0 at full throttle)

OS switching wire (applicable for closed loop - dont know if this applies to gti6 but the 4 wires seem to suggest it does but unsure): should show a wave form switching from ~200 to ~800 mV at a ~1Hz frequency.

 

As i understand it if the sensor is failing to 'switch' the parameters will be in a range (so no warning) but will not run right.

 

All the above is from a book not my knowledge and am unsure if I am applying it corectly - I have not even tried to carry out any running tests (or any at all yet on o2), I am not a mecahnaical or electrical guru (by a long long way!).

 

Am not going to admit to how much I have paid for the oe one from pug - double what you paid though

[pug_ham 244 3 Cars]

The test I mentioned above is for a four pin lambda & taken from the autodata pages for a 1997(97-01) 306 GTi-6 so it should be right for your loom, engine & lambda.

 

For the heated o2 sensor you should get 0.1-1v fluctuating across pins 3 & 4 at idle.

 

For the oxygen sensor it gives two tests, one to check the supply voltage from the relay & the other to chack the resistance of the lambda.

Pins 1 & 2 on the lambda loom plug should give 11-14v with pins 9 & 11 bridged on the relay (feul pump fuse removed) & use the test in my previous reply for the resistance.

 

I've no idea what could cause the high co if the lambda & CTS both test fine unless its a faulty ecu or something but air leaks in the exhaust can cause artificially high CO readings afaik.

 

I've had problems getting my GTi through due to high co when the book figure states my ecu as standard should give under 2% co iirc but it was just over 3.5% for the last test which I lowered by fitting a freshly cleaned & re-oiled air filter & tweaking the co pot because when I took it back but it was still over. I eventually got it down to under 3% but expect the same again next year if the same engine & ecu are still fitted. I had intended to take it back to Wayne for him to make a special low co chip just for the MOT but when I failed to get in touch with him after initally arranging to call him & discuss it I managed to get the co low enough so I didn't need to bother.

 

Graham.

[BuD 0]

Cheers again mate - great info.

[BuD 0]

Bad news for me

 

Got new lambda sensor and no change at all.

 

Have been at peugeot this morning to test the emmisions and it fluctuates from 4.xx to 6.xx on the analyser. HC is still fine. They are now pretty certain it needs a cat fitted to acheive under 3.5% CO, they also tell me that my readings are pretty much identical to a modern peugeot with a failed cat. My engine is not running rich, its lambda value is spot on.

 

I am now of the opinion that my GTi6 (and very likely others too...) need a CAT to pass the MOT. Not a single 205 GTi6 owner has posted on this topic saying theirs gets good CO readings without suggests to me they are either using Cats or are freindly with the tester!

 

This suprises me as I would have thought a modern engine would breeze the non cat test but it seems to not be the case.

 

EDIT:

 

i'd say a cat would cure that too but they are expensive (well, good ones are).

 

I mot'd a 407 2.2 dw petrol the other day which failed on similar readings which was down to a faulty cat. The annoying thing is that car drives 100% perfect, just emisions were sky high

 

seems imo you were right!

Edited October 3, 2008 by BuD

[welshpug 1,657]

does still seem a tad rich looking at the CO value

 

you need some input from all those 2.0 engined puggers! (including turbo's as they were intended to run a CAT)

 

wild stab in the dark, check that the fuel pressure regulator vacuum hose is fine and the pressure reg isn't damaged, I've seen that cause problems on an 8 valve engine.

 

another thing that may cause odd readings is a dicky Throttle position switch.

[CaptainK 11]

Most weird indeed. My 205 GTi6 MOT at very high emissions. I changed the engine coolant sensor and the lambda and it shot right down. Was about 6% or summat and it shot down to 0.6%. This is with a sports cat fitted however.

 

On the flip side, my FTO GPX has no CAT and passes its test with 0.06%.

[BuD 0]

Went to my local exhaust place today to try to make a cat exhaust using 306 cat plus 205\306 exhaust bits.

 

We didnt even take the old one off in the end as there was no chance of getting the 306 cat in. Also the cat was £141 and the multiple hours of labour needed to make a pretty naff exhaust meant we decided it wasnt the right option.

 

We decided the best option was have my non cat stainless exhaust modifed so a cat could be inserted and easily replaced by a de-cat pipe. This was something they did not want to do. I have magnaflow near me so planned on taking it there but unfortunately they dont have a mechanic at the moment so cant do any fabrication.

 

Have decided that there is no chance of getting it fixed and retested by this friday so am going to have to sorn it for a bit

 

Am probably going to get Des Developments to have a look as Neil supplied the exhaust and did a lot of the wiring for me (and did a very good job).

Edited October 7, 2008 by BuD

[Anthony 1,003]

Have been at peugeot this morning to test the emmisions and it fluctuates from 4.xx to 6.xx on the analyser. HC is still fine. They are now pretty certain it needs a cat fitted to acheive under 3.5% CO, they also tell me that my readings are pretty much identical to a modern peugeot with a failed cat. My engine is not running rich, its lambda value is spot on.

 

I am now of the opinion that my GTi6 (and very likely others too...) need a CAT to pass the MOT. Not a single 205 GTi6 owner has posted on this topic saying theirs gets good CO readings without suggests to me they are either using Cats or are freindly with the tester!

With the emissions fluctuating by 2% odd I would say that there's a problem unrelated to the lack of CAT, but having never checked the emissions on a known-good GTi-6 without a CAT it's hard to say - certainly the fluctuations don't sound at all right though.

 

For what it's worth, I know that my 306 S16 would have very easily passed a non-CAT test with a "de-CAT" fitted (well, it was actually a CAT that the internals had disintegrated on and blown out of the back, leaving a hollow straight-through CAT casing). I can't remember the exact figures now as it was a couple of years back, but it was definately below 1% CO - it wasn't far off passing a CAT test, I remember that much.

[Garry 1]

Sorry, just seen this thread.

 

Mine always has high emmisions, a couple of years ago I changed the CTS which dropped it to around what you are getting. Other than that the car is healthy, I have run it for about 4 years now, Miles has just had the head off and says it is in pretty good nick, so i doubt there is anything to worry about.

 

I now get MOT's by taking the seats out of the car bar the drivers seat, that way it is no longer a passenger vehicle and the emmisions are more leniant, a bit dodgy I know but it is an option.