How do you replace diesel additive in a puegoet 307 hdi?

There's no routine "replacement" of diesel additive in a Peugeot 307 HDi (or most modern diesel vehicles). The additive is usually incorporated directly into the diesel fuel itself at the refinery or distribution point. You don't add a separate bottle of additive to the tank like you might have in older vehicles or with some specific fuel treatments.

If you're experiencing problems with your Peugeot 307 HDi that you suspect are related to fuel quality, consider these options:

* Use higher-quality diesel: Using fuel from a reputable supplier known for better quality diesel fuel can often resolve issues. Cheaper fuel sometimes contains lower-quality additives or even lacks them altogether.

* Fuel system cleaner: If you suspect a build-up of deposits in your fuel system (injector issues, etc.), a fuel system cleaner *might* help. However, always follow the instructions carefully as these cleaners are strong and using them incorrectly could damage your engine. Consult your owner's manual or a qualified mechanic before using a fuel system cleaner.

* Professional inspection: If you're having ongoing problems, take your Peugeot 307 HDi to a qualified mechanic. They can diagnose the actual cause of the problem, rather than just assuming it's a lack of additive. Many issues mistaken for poor fuel quality stem from other problems like clogged fuel filters, faulty injectors, or other mechanical issues.

In short, don't try to "replace" a diesel additive in your Peugeot 307 HDi as there's nothing to replace in the conventional sense. Focus on using quality fuel and seeking professional help if you encounter problems.