Bit of a random one I know, but as this is an almost unknown issue that is such an easy fix, I thought it best to mention...
Now this issue predominantly affects TDI models, but also has the potential to affect petrol models as well, and specifically relates to the electrical plug connection to your MAF - Although any sensitive electrical component that relies on a multiple feed electrical signals can be affected.
A lot of people complain of issues of rough or lumpy running on their cars despite changing multiple parts and tuning etc (I was one of them). After months of tweaking & monitoring using VCDS I was still none the wiser as to why my car didn't feel quite right even after removal & replacement of parts including inlet manifold, EGR, and MAF.
Some late night reading lead me to investigate the MAF connector itself. Now the connector is a fairly robust item, nothing fancy, & typically standard of the type of connector used across the car - which is where the actual problem lies. Other than keeping the individual electrical contacts apart from each other, it contains absolutely no electrical insulation of any kind. Which means that connecting to such an electrically sensitive piece of equipment (MAF), the potential for cross signal or 'electrical contamination' across the plug connector is extremely high. It's these mixed or contaminated signals that cause the issues...
The resolution, costs around £3 & 5 minutes of your time... Simply remove the MAF connector, blow out any crud that may be inside, or give it a blast of contact cleaner if you have it. Now apply Dielectric silicon grease (It must be dielectric specifically) into the electrical contacts on the plug with your finger to fill the connections. Replug the connector & your done! I was a massive sceptic of this actually working, but unbelievably it has! My car is now has no more glitching or lumpiness, it's no more powerful, just super smooth. I'm now in the process of applying the grease to any other connections I can find in the engine bay (every little helps etc).
How it works: The dielectric grease is an electrical insulator, by filling the contacts you are ensuring that there is no electric/signal bleed across the connector & the only signal transfer can be from direct metal contact to metal contact. This ensures a 'clean' signal from MAF to your ECU & correct fuelling at all times.
This may not be the resolution to all of your issues, however for the money & time involved it should be a priority to investigate.
Now this issue predominantly affects TDI models, but also has the potential to affect petrol models as well, and specifically relates to the electrical plug connection to your MAF - Although any sensitive electrical component that relies on a multiple feed electrical signals can be affected.
A lot of people complain of issues of rough or lumpy running on their cars despite changing multiple parts and tuning etc (I was one of them). After months of tweaking & monitoring using VCDS I was still none the wiser as to why my car didn't feel quite right even after removal & replacement of parts including inlet manifold, EGR, and MAF.
Some late night reading lead me to investigate the MAF connector itself. Now the connector is a fairly robust item, nothing fancy, & typically standard of the type of connector used across the car - which is where the actual problem lies. Other than keeping the individual electrical contacts apart from each other, it contains absolutely no electrical insulation of any kind. Which means that connecting to such an electrically sensitive piece of equipment (MAF), the potential for cross signal or 'electrical contamination' across the plug connector is extremely high. It's these mixed or contaminated signals that cause the issues...
The resolution, costs around £3 & 5 minutes of your time... Simply remove the MAF connector, blow out any crud that may be inside, or give it a blast of contact cleaner if you have it. Now apply Dielectric silicon grease (It must be dielectric specifically) into the electrical contacts on the plug with your finger to fill the connections. Replug the connector & your done! I was a massive sceptic of this actually working, but unbelievably it has! My car is now has no more glitching or lumpiness, it's no more powerful, just super smooth. I'm now in the process of applying the grease to any other connections I can find in the engine bay (every little helps etc).
How it works: The dielectric grease is an electrical insulator, by filling the contacts you are ensuring that there is no electric/signal bleed across the connector & the only signal transfer can be from direct metal contact to metal contact. This ensures a 'clean' signal from MAF to your ECU & correct fuelling at all times.
This may not be the resolution to all of your issues, however for the money & time involved it should be a priority to investigate.