Depollution system faulty And P0504

[xrocker2002]

A quick question..

Depollution system faulty And P0504 are inter-related??

FUEL INJECTOR CLEANERS are really useful for petrol Peugeot car??

What is the optimum speed for Peugeot 308 Turbo hatchback car for maximum mileage??

[GiveMeABreak]

1) No, P0504 relates to the brake pedal switch - coherence fault between the 2 brake sensors detected under acceleration.
2) Generally speaking, around the 56-60 Mph. Once you go over this economy starts dropping, and at anything above 80+ mph and your economy will start to drop significantly more. This will depend on your engine and gearbox:- manuals get more mileage than an automatic. City driving is not so good as there is a lot of stopping and starting. Motorways or long roads are better so you can maintain a constant speed. Low rolling resistance tyres also make a difference that are correctly inflated, and not carrying a lot of unnecessary weight in the car also helps.

[xrocker2002]

Thanks for the reply

[xrocker2002]

As per your 2nd reply, Is it preferable to use Diesel Fuel injector cleaner for Petrol Car??

[GiveMeABreak]

No!

Only use Petrol Injection system cleaners specifically for Petrol engines
Only use Diesel Injection system cleaners specifically for Diesel engines

I only mentioned the diesel cleaner specifically as it is important that IF you have a diesel car with a Diesel Particulate Filter, it is important to ensure it is suitable for these engines.

To avoid confusion, I've removed my reference to diesels in my original reply as it was confusing - sorry about that.