

Here’s a great article from Popular Mechanics on how to detect a vacuum leak. Also, since a vacuum leak almost always affects each cylinder the same, you’ll typically get P0300 with it and not any cylinder specific misfire codes. This will cause the cylinders to misfire and it’ll throw the P0300. Vacuum leak– If your Aygo has a vacuum leak, it can be very difficult for it to get the right air/fuel mixture.Here’s some information on how to tell if you have a bad fuel filter. But, it’ll sputter and act like it’s going to die at speed or under heavy acceleration. Typically, if you do have low fuel pressure, the vehicle will act fine when it doesn’t need a lot of fuel. Diagnosing low fuel pressure can be tricky. Low Fuel Pressure– If there isn’t enough fuel getting to the engine, this will cause combustion to be less than optimal.They are presented somewhat in order from most to least likely to be causing the code: Here are the most common problems that will throw the code.

PO 300 CODE
There are quite a few things that can cause the P0300 trouble code to trigger the Toyota Aygo. P0300 Trouble Code Diagnosis- Toyota Aygo

P0300 : Random, Multiple Misfire Detected P0300 is a very common OBDII codes that occurs with the Toyota Aygo.
