Thanks All

Nodge68 wrote:

The main reason the TB is there, is to improve functionality of the EGR circuit, the other benefits (reducing NVH) are of minor consideration, and to most normal people, the engine would seem to run just as well without it.
In fact when an ERG delete was fitted to the TDV6 used in the D3/4, it was normal practice to simply remove the TB butterfly at the same time, as it also has problems with gear stripping, and once the EGR is blanked, it serves no other real purpose, except for the minor improvements in NVH detected with specialist equipment.

No. The reason the EGR gums up is because diesel fuel is not clean burning.
Also the inlet manifold fills with goop because of oil in the air from the breather system, which is partially burnt by the hot gas from the EGR system.

Unfortunately the intake manifold will only stay clean, if the EGR is disabled altogether. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.