Toyota Previa d4d engine issue

[Bryc]

Hi, I have a 2006 Toyota Previa with the d4d engine. Whilst driving it can struggle to accelerate just at random times, if you keep your foot to the floor it will clear and pick up power like normal. Sometimes won’t happen for a few weeks then can just start happening. No codes are coming up

[Cyker]

It's likely some sort of restriction somewhere; In the earlier D4Ds it's usually something vacuum line or EGR-related. My 1.4 D4D's throttlebody had a little hole/port that went to the EGR and it was blocked with soot, causing a very uneven idle and weird power fluctuations.

The EGR itself was pretty sooty, and we thought that was the issue originally, but cleaning it didn't help.

 

[Bryc]

Thank you, I will have a look to see if that will sort the problem.