Changed The pre-cat Lambda sensor today for bosch one and noticed the connector at the front of the gearbox, one of the pins is dettached and corroded - what is the connector on the front of the gearbox? -speed sensor? if so whats the part number?

no change with lambda sensor at all. Not going to take it off though.. going to get the new sensor on the gearbox and map sensor too..

vagcom results after changing front lambda are

17526 - oxygen (lambda) sensor heating bank 1 sensor 2: open circuit

16705 - engine speed sensor (g28): Implausable signal

17978 - engine start blocked by immobiliser

17549 - load calculation cross check: Implausable Value

16556 - system too rich, bank 1

6556/P0172 - System Too Rich, Bank 1

Edited 12 March, 201511 yr by rosshall22

I gave this a read but that refers to error code 16706 which is the sensor lcated next to the strater motor they do also mention the camshaft sensor which is £25 so I'm going to try with that one first as the other seems awful to get too..

http://www.tigerstyle.co.uk/phpBB3/viewtopic.php?f=13&t=48197

The connector ( 2 pin) on the front face of the gearbox is the reverse light switch

I assume you did the throttle body adaption first before changing parts - how did it run after that ?

17526 refers to the rear lambda sensor - you don't have one fitted so it will be open circuit

16705 refers to the G28 speed sensor - better known to me as the crank position sensor.

I posted some pictures about the replacement of the crank position sensor in this thread http://www.clubpolo.co.uk/forum/index.php?showtopic=336306&hl=

This job is theoretically very easy, but can be an absolute pig of a job in practice. Losing the crank position can easily cause poor / non running problems. Looking at the codes I think you are wasting you money on a cam position sensor

Did you clear the codes before a re-scan ?

yeah all cleared and now nothing is coming up. I Haven't changed the crank position sensor yet removed the two fuel pipes to get to map sensor and the pipe into the MAP wasn't even attached! going to clear any codes again then start her up if the problem persists I'm gonna go ahead and change the map sensor first. Then clear codes before starting with crank sensor.

Sounds promising.........................

I can't do the throttle body adaption on the lite version so can't guarantee that isn't causing an issue. I changed the MAP sensor and went to clear the codes as the previous didn't work ^ Turned laptop back on and ended up bluescreening! So not only dead 6N2, dead laptop too!

I'm going to sort the laptop then reset any codes and see how she goes. That links really detailed, definitely don't fancy attempting that I think I'm going to have to get the upgrade and do the throttle body adaption.. I didn't realise it wasn't 'plug n play' type connection

You can get around the TB alignment by driving the car for around 20 mins using varying throttle loads, the ECU will re-learn the settings and be OK

sorted the latop out today and did another scan So currently have only changed pre-cat lambda and MAP sensor.

16726/P0342/000834 - Camshaft Position Sensor (G40): Signal Low

17526/P1118/004376 - Oxygen (Lambda) Sensor Heating; B1 S2: Open Circuit

17549/P1141/004417 - Load Calculation Cross Check: Implausible Value.

16556/P0172 - System Too Rich, Bank 1

17564 - Manifold Pressure Sensor (G71) <<<????? not on ross-tech

17978/P1570/005488 - Engine Start Blocked by Immobilizer.

16845 P0461. Fuel Level Sensor Circuit - Range/Performance. <<<????not on ross-tech

cleared the codes and only one remains

17564 - Manifold Pressure Sensor (G71) <<<????? not on ross-tech

(17526)

Going to try and go for a drive and try.....

You can get around the TB alignment by driving the car for around 20 mins using varying throttle loads, the ECU will re-learn the settings and be OK

wish me luck on not having to call greenflag out!

Edited 13 March, 201511 yr by rosshall22

Didn't make it half a mile and no way of getting it back home now withou breakdown being called! drove the half mile fine at 2000rpm then came to a junction it stuttered and revs hunted and died then no power to start the car again. temp rose to 90'c no sign of the fan though.. Left it until it cools down to try and start it again. Also reading other topics I can see a separate issue to not starting whilst warm... are coolant temp sensor. £39.12 with o-ring from vw, but as I'm not getting a code I'm going to wait til i get it back home to rescan!

http://www.clubpolo.co.uk/forum/index.php?showtopic=309740

and...

QUOTE (howard1999 @ Monday 4th March 2013 - 7:16pm) <{POST_SNAPBACK}>

Hi, I'm wondering if anyone could shed some light on this problem for me. I have a 6n2 16v and it has a fluctuating idle and sometimes when its in high revs when driving it will cut out and stop and I have to start the engine again. The engine management light comes on and off on the dash from time to time. The advice that I have been given so far is that its is probably the throttle body. I was wondering if anyone else has had similar issues and has resolved them.

Cheers

I've had the same sort of problems and without using a diagnostic scanner your hitting and hoping

Temp Sensor (located to the front of the engine)
Coilpack (located to the right of the rocker cover)
Knock Sensor (located on the right of the started, circle sensor looking thing)
Engine speed sensor (located on the flywheel behind starter)
Camshaft speed sensor (located on top of the rocker cover)
Camshaft position sensor (located on top of the rocker cover)

you can buy a cheap vag diagnostic scanner on ebay for around £10-£20

best money you could spend as gives you the codes and you look on google for the code and normally your find it as it will be a common fault.

Keep telling myself,,,, THE HARDER THE BATTLE, THE SWEETER THE VICTORY - Revolver!

Edited 13 March, 201511 yr by rosshall22

Did you ever fixed the breather pipes

Didn't make it half a mile and no way of getting it back home now withou breakdown being called! drove the half mile fine at 2000rpm then came to a junction it stuttered and revs hunted and died then no power to start the car again. temp rose to 90'c no sign of the fan though.. Left it until it cools down to try and start it again. Also reading other topics I can see a separate issue to not starting whilst warm... are coolant temp sensor. £39.12 with o-ring from vw, but as I'm not getting a code I'm going to wait til i get it back home to rescan

Did you get the car back home yet ?

When you say "no power to start the car again" what exactly do you mean. Would the engine not turn over because the battery was low voltage / flat ?

I suggest you do a rescan, check battery voltage, let us know if you fixed the breather pipes as residentmelon suggests, and if the car still won't start then identify if the problem is fuel or spark first. Silly question, having missed the obvious myself in the past, you do have sufficient fuel in the car don't you

On the throttle body there are two vacuum pipes for abs as one goes to servo and the other goes to a cylinder tank (reservoir?) in front of drivers side wheel arch. the pipe going to this reservoir came off the male connection quite easily even with jubilee in place - could this be the vacuum leak also affecting abs? (i know 6n2s are prone to sensors)

The breather pipe doesn't have anywhere to go with my BMC DIA and it doesn't have a filter on the end... Its been like this since I got it last year and didn't seem to cause concern except the smell sometimes sat at traffic lights.

Just re-reading the thread, what's the connection like to the "cylinder tank in front of the drivers wheel". It's actually not for ABS but an emission control system for gases from the fuel tank

Breather pipe was ok to the sensor then no pipe to airbox/no breather filter. The same as described above - I have the original airbox just no filter.(possibly causing vacuum leak/intake leak as doesn't sense the pressure of intake air).

Got the car home late last night all it needed was a booster pack as battery had died completely flat no digital info or needle movement. Definitely just below half a tank the needles still working.

Will do a rescan tomorrow as been out today and came home with another 6n2 gti from ebay. ARC engine code ( mecahnically sound (albeit sitting low 70'C temp or less until sat in traffic then eventually 90' and steady! then back down cold) - bodywork dents and scuffs here there and everywhere!

The connection on the top of that tank is tight but slight 'engine dirty greasy' around the two connector funnels and slightly on top of the tank. I'll give that a proper look over and clean too. I guess just wait for the scan results to see whats still wrong..

Cheers gents

When you get the car started check the voltage that the battery is being charged at. If the alternator is below par then that can affect the ECU...........

If the pipe to the petrol tank emission control is not connected, then temporarily block it off by putting a bolt in to seal the pipe. No air filter will not affect the sensing of the inlet manifold pressure, having a pipe open to atmosphere will.

Post some more pictures of the components / missing pipe location so we are sure what bits you are talking about

You now have the advantage that you can compare VCDS results across cars too

Just wondering if you have made any progress on this ?