mot fail on emissions and fault codes

[alanh6687]

*UPDATE*

Activated full vag com, did the alignment... Still the same....

Had complete look over the engine for split pipes. Found a pipe split (split was hidden right at the back of it)

The pipe was underneath the inlet manifold. Just removed it.. part number: 06A 103 221 AF

Any idea how much and where I can get one cheap????

 

[8bit]

Could try TPS (Trade Parts Specialists) if there's a branch near you. Wouldn't have thought a pipe or hose would cost much even from the stealers tho.

Good find although shame the throttle body reset didn't fix it. Full vag com will come in handy though and you can keep a look out in the help requests bit of the Vag Com section of this forum. Some folks will happily give you a few quid for your time so it might pay for itself.

 

[alanh6687]

Bought the pipe from TPS this morning and fitted it. Reset codes and started the car... Still the same

Getting random misfire and misfire on cylinders 1,2 and 4. Swapped some coilpacks around and still same codes.. Cleared again and they've not returned yet..

Only seems to be lumpy or misfire at idle and when you first turn the car on hot, weather its hot or cold at the minute?

 

[8bit]

Can you log the car to show your mass airflow g/s figures, for a minute or two at idle and then on a 3rd or 4th gear run, 1200rpm to redline? Just so we can see what the MAF readings are. I know you said you'd changed it recently but I've heard of new ones being duff from day one. Might be worth logging the correction factors as well. Blocks 002 and 015 I think.

Does the idle settle down after a while? What spark plugs have you got in there?

 

[alanh6687]

I'll try and log it on monday. I left the car at work over the weekend. Its doing my head in

Its got the NGK spark plugs in it, only about 3 months old :s

When I start the car the idle shoots to 2k, then goes to around 1k, going up and down slightly. Its not as bad as it first was but its still coming up with the misfire codes

 

[8bit]

What heat grade are the plugs? Is your car remapped?

As for your idle issues, could be coolant temp sensor. Worth having a search for that, it was covered a lot of times over the winter but I never had an issue with mine so no first hand experience. I know you can sometimes find the prongs in the coolant tank get covered in gunk, if I remember rightly some folks have managed to clean theirs by scraping with a flat-blade screwdriver, but be careful not to break them.

 

[twenny]

alright mate

listen to what vag coms telling you , i reckon your o2 sensors knacked , once warm the o2 sensor and throttle position sensor have the most authority on fueling , youve reset your TB , and no better , the fact youve a decat have you banged the o2 sensor itself or the wiring when fitting ??

cts and air temp sensors have priority on cold star, 8 bit mate ,it seems ok on cold start i think , so id say o2 sensor

have a look at the wiring and the sensor for any obvious damage , but even then you cant always see .

hope this helps mate

twenny

 

[8bit]

Ah, I misread where alanh said "Only seems to be lumpy or misfire at idle and when you first turn the car on hot, weather its hot or cold at the minute?" as being that it was misfiring or lumpy at startup regardless of whether it was hot or cold, my bad. Didn't realise lambda sensors were that fragile either.

 

[twenny]

Alright 8bit ,

yeah there very fragile as are most sensors bud . google how a o2 sensor works and whats inside bud and youll see ther pretty delicate things

not sure meself what he means now lol, i took it as starting the car hot regardless of the weather been hot or cold ?


either way id be looking at o2 ,symptoms wise and the fact vag com is saying malfuction of o2 . and given the fact he's changed what he has ruling other things out sways me more .

Thats just my opinion fella , might be wrong ,could be somthing else entirley

hope he gets it sorted

all the best

twenny

 

[alanh6687]

alright mate

listen to what vag coms telling you , i reckon your o2 sensors knacked , once warm the o2 sensor and throttle position sensor have the most authority on fueling , youve reset your TB , and no better , the fact youve a decat have you banged the o2 sensor itself or the wiring when fitting ??

cts and air temp sensors have priority on cold star, 8 bit mate ,it seems ok on cold start i think , so id say o2 sensor

have a look at the wiring and the sensor for any obvious damage , but even then you cant always see .

hope this helps mate

twenny

Hi. I replaced the precat lambda sensor a couple of weeks ago and didn't solve the problem I've not got a decat on it at the minute mate

 

[alanh6687]

What heat grade are the plugs? Is your car remapped?

As for your idle issues, could be coolant temp sensor. Worth having a search for that, it was covered a lot of times over the winter but I never had an issue with mine so no first hand experience. I know you can sometimes find the prongs in the coolant tank get covered in gunk, if I remember rightly some folks have managed to clean theirs by scraping with a flat-blade screwdriver, but be careful not to break them.

The spark plugs are just the standard ones, not sure of grade.

It has been remapped at a place called more bhp in Crewe

I replaced the coolant temp sensor about 5-6 weeks ago

 

[twenny]

ahh sorry mate ,

good luck then fella didnt realise you had .

all the best fella

twenny