how to replace a gloplug 2017 Tiguan Mk2 2.0 TDI : Cylinder 4 Glow Plug Circuit P0674 00 [237] - Electrical Fault

 almost as soon as i deal with the air sensor up pops another fault (to be fair I have seen it before, but cleared and ignored it)

4987 - Cylinder 4 Glow Plug Circuit (Q13)
          P0674 00 [237] - Electrical Fault
          MIL ON - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 6
                    Mileage: 80683 km
                    Date: 2022.11.20
                    Time: 12:58:13

                    Engine RPM: 913.00 /min
                    Normed load value: 27.5 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 12 °C
                    Intake air temperature: 13 °C
                    Ambient air pressure: 1000 mbar
                    Voltage terminal 30: 11.640 V
                    Unlearning counter according OBD: 40
                    Electric auxiliary heater: shut-off conditions-Bits 0-7: 0
                    Electric auxiliary heater: shut-off conditions-Bits 0-7: 0
                    Electric auxiliary heater: relay activation-Bits 0-7: 0
                    Pre-glow time: 2100 ms
                    Glow status-Bits 0-7: 0
                    Glow status-Bits 0-7: 176
                    Glow cycles above temperature threshold-Bits 0-7: 0
                    Glow cycles above temperature threshold-Bits 0-7: 2
                    Glow cycles below temperature threshold-Bits 0-7: 0
                    Glow cycles below temperature threshold-Bits 0-7: 0
                    Outside temperature sensor 1: B1: raw value: 9.0 °C

apparently 3 are normal gloplugs and one is special (normally cylinder 3) which an an additional sensor and is much more expensive

Luckily this is cylinder 4
Should really change as a set, but this time Im going to wing it.

2 parts I needed to buy

1. New Bosch gloplug (ECP partno 438 44 0017) from EuroCarParts : £14.99 inc VAT
2. Draper 16579 Metric 3/8-Inch Square Drive Hi-Torq 6-Point Deep 10 mm Socket  https://www.amazon.co.uk/gp/product/B072JTMVYC

useful video

https://www.youtube.com/watch?v=28QsRx5HJ-c

• 5-10 min job
• engine cover pull off
• pull off glopplug connector
• use air line or pipe to blow out any debri in plug hole
• remove/replace gloplug (make sure you compare them side by side for similarity)
• repeat steps in reverse
• clear DTC 
• make a brew

Heres the new and old and 10mm socket