Hello,

I've got a pretty annoying issue with my 2003 Octy 4x4 turbo.
I'll be driving down the road and the car stalls when sitting at a red light idling.

The symptoms that have been common every time it has done it (third time now) is as follows:
- Stalls, EPC light and battery light on
- Tough to start
After starting again:
- High idle between 1200rpm and 1500rpm
- Low power
- won't rev past 4000rpm

- EPC light on
Also these problems go away after re-starting the car again. The car has been up to temperature every time this has happened.

Does not seem to happen in the morning for some reason. Could be dumb luck.

I suspect it may be throttle body but I've been researching and I'm getting conflicting answers (such as MAF, throttle pedal assembly, coilpacks, etc). So I figured I'll post another thread for my specific issue.
I'll add I have a spare throttle pedal assembly (drive by wire) that I can toss in.
No access to VCDS at the time of writing this. I have a generic ELM327 scan tool.

Suggestions, insights and solutions are much appreciated.

Try with your ELM scan tool to see if there is any error number. In our cars this can be caused by a bunch of things as you have already discovered. 

 

I had that (or similar) issue with my wife's 2000s Mergane Coupe 1,4 and it was the throttle body sealing ring. It was dried out letting air came into with all awkward issues. High revs, stalling, sometimes low power, sometimes over power etc. Replaced the O-ring of the throttle body and car purrs like a kitten now.

1 minute ago, stratosg said:

Try with your ELM scan tool to see if there is any error number. In our cars this can be caused by a bunch of things as you have already discovered. 

 

I had that (or similar) issue with my wife's 2000s Mergane Coupe 1,4 and it was the throttle body sealing ring. It was dried out letting air came into with all awkward issues. High revs, stalling, sometimes low power, sometimes over power etc. Replaced the O-ring of the throttle body and car purrs like a kitten now.

Thank you for your reply. I did a scan about a week ago when this first started and here is the output:

Car Scanner ELM OBD2
DTC report
Selected brand: Skoda

============1==============
P0037
Raw code: 0037
ECU: OBD-II
Status: Confirmed
OBDII: Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit low
Skoda: HO2S Heater Circuit Low Voltage Bank 1 Sensor 2

============2==============
P0141
Raw code: 0141
ECU: OBD-II
Status: Confirmed
OBDII: Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit malfunction
Skoda: HO2S Heater Performance Bank 1 Sensor 2

============3==============
P1296
Raw code: 1296
ECU: OBD-II
Status: Confirmed
OBDII: Multi-faults - Bank 2 - With Low Side Shorts
Skoda: Cooling system malfunction

 

Well it seems you have an electrical issue with the H02S heating circuit. Take a look here 

 

Also  

https://www.carobdcodes.com/skoda-p0037-ho2s-heater-control-circuit-low-bank-1-sensor-2.shtml

https://www.carobdcodes.com/skoda-p0141-o2-sensor-12-heater-performance.shtml

 

Finally for the P1296 watch the video below. 

 

I would do a switching voltage check across the post cat lambda sensor. Usually when the codes for the internal heating element present themselves, then the actual lambda sensor function itself is not long from failure either.

 

The coolant code can be either temperature sender or the thermostat itself in more extreme situations. Does the car reach 90 degrees and stay there or does it fluctuate on gradients, especially coasting downhill?.

33 minutes ago, kentphil1 said:

I would do a switching voltage check across the post cat lambda sensor. Usually when the codes for the internal heating element present themselves, then the actual lambda sensor function itself is not long from failure either.

 

The coolant code can be either temperature sender or the thermostat itself in more extreme situations. Does the car reach 90 degrees and stay there or does it fluctuate on gradients, especially coasting downhill?.

The thermostat was replaced when I last serviced the car (a month ago). It reaches and maintains 90*C no problem.
I'll see if I can lay my hands on a multi-meter.

Update:
Since I posted I have replaced the throttle pedal sensor, which made the car drive a lot better but didn't remedy the issue.
I tried cleaning the throttle body, which helped for about two days before it started acting up again.
So with that in mind, I suspect it may be the throttle body acting up. Which would explain the random stalling.

2 hours ago, nothy said:

Update:
Since I posted I have replaced the throttle pedal sensor, which made the car drive a lot better but didn't remedy the issue.
I tried cleaning the throttle body, which helped for about two days before it started acting up again.
So with that in mind, I suspect it may be the throttle body acting up. Which would explain the random stalling.

To add to this - Also ordered a VCDS compatible cable today. Will update when it arrives.

Update - A wild new fault code has appeared! The crankshaft position sensor is faulty. Solved I guess?
 

The crank sensor would explain the difficult starting, but you still have looming lambda probe issues. I would delete all codes after saving a copy of your scan, run for few days, then rescan to see what returns.

 

Some of the codes when deleted have to complete several duty cycles (read start/stop with the ignition key) before they will return, but defective safety items will return immediately.

 

What fault code did the crank sensor return and its description, as the code will divide into defective or intermitent?. Having said that, if it was showing defective I wouldn't expect the car to start at all.

 

Does your VCDS lead and version allow you to do data logging or it VCDS lite with an aftermarket cable?.

51 minutes ago, kentphil1 said:

What fault code did the crank sensor return and its description, as the code will divide into defective or intermitent?. Having said that, if it was showing defective I wouldn't expect the car to start at all.

P0322
Status: Confirmed
OBDII: Crankshaft position (CKP) sensor/engine speed (RPM) sensor - no signal
Skoda: IC Module 4X Reference CKT No Frequency

Does not seem to specify that it is intermittent, but the car does lose RPM signal when the car tries to stall out but recovers
 

53 minutes ago, kentphil1 said:

Does your VCDS lead and version allow you to do data logging or it VCDS lite with an aftermarket cable?.

I do not know yet, it hasn't even left the store I ordered it from. I will be running VCDS lite though so I assume I can't do data logging

Attached a screenshot of OBD scan. Disregard P1296 as it is solved (replaced thermostat), it just completely slipped my mind to clear the code(s) last time I scanned.

Some info on your crank sensor fault code - http://wiki.ross-tech.com/wiki/index.php/16706/P0322/000802

 

2 minutes ago, kentphil1 said:

Some info on your crank sensor fault code - http://wiki.ross-tech.com/wiki/index.php/16706/P0322/000802

 

Spot on symptoms. My car stalls an awful lot and simultaneously loses RPM signal if it recovers

Whilst it most likely is a defective sensor at the age of the car, you would be wise to heed the comments about checking the loom and connector first, as corrosion in the connection is also likely.

 

Hope it helps.

 

On 17/12/2021 at 21:31, kentphil1 said:

Whilst it most likely is a defective sensor at the age of the car, you would be wise to heed the comments about checking the loom and connector first, as corrosion in the connection is also likely.

 

Hope it helps.

 

Solved. Took her to a mechanic, he replaced the sensor (tried it myself, couldn't get in there without breaking the dipstick). 50€ to get it sorted.
He checked signals and such, too.