Technical P0300

[VinceB]

Fiat 500 2011 1.2 lounge
Bought this car 3 weeks ago and was running great until today.
Start stop switching itself off ? Warning light triangle and engine light showing on display running lumpy code P0300 and P0302 P0303 suggesting first stop is the plugs but I fear it could be more and likely to have been experienced by other owners so advise appreciated oh they lights go out runs for few mins and turn back on and car sluggish have I bought a money pit?

 

[cainy1989]

Start with the basics and check the plugs, if it's misfiring on two out of four it's likely to be something a little more than plugs and coils. Was it a dealer or private sale?

 

[VinceB]

Start with the basics and check the plugs, if it's misfiring on two out of four it's likely to be something a little more than plugs and coils. Was it a dealer or private sale?

Hello thank you for replying it was a private sale it was running lovely when we bought it . There was an issue with the high level breaking light not working the man who sold the car came back and fixed that he said it was the tailgate wiring loom thing? It’s a lovely car just don’t work properly

 

[steveras57]

First checks are!- plugs, coil pack, main earth strap, and then hatch wiring! could also be blocked/failing fuel injector(S)

 

[VinceB]

First checks are!- plugs, coil pack, main earth strap, and then hatch wiring! could also be blocked/failing fuel injector(S)

Thank you Steve
Started it this morning little high idle it then settled below 10 bit lumpy then went off to Halfords round trip about 6miles no warning lights smooth as you like I’m double confused I’ll change plugs later then if a reoccurrence I’ll continue with your suggestions

 

[steveras57]

Thank you Steve
Started it this morning little high idle it then settled below 10 bit lumpy then went off to Halfords round trip about 6miles no warning lights smooth as you like I’m double confused I’ll change plugs later then if a reoccurrence I’ll continue with your suggestions

might be worth running a bottle of good quality injector cleaner through the motor before swapping out other parts!

 

[VinceB]

might be worth running a bottle of good quality injector cleaner through the motor before swapping out other parts!

Thanks will do is there any recommendations on injector cleaners

 

[steveras57]

Thanks will do is there any recommendations on injector cleaners

Liquid moly or S T P both available online! add to a full tank of the best E-5 petrol (I use Esso supreme as it contains NO Ethenol at present even though pump says E-5!) once its in there drive the car with some spirit! IE- use the revs through the gears to get the injectors at full flow ! you know an Italian tune up!.

 

[VinceB]

Liquid moly or S T P both available online! add to a full tank of the best E-5 petrol (I use Esso supreme as it contains NO Ethenol at present even though pump says E-5!) once its in there drive the car with some spirit! IE- use the revs through the gears to get the injectors at full flow ! you know an Italian tune up!.

Haha thanks I’m off to Halfords n Esso

 

[steveras57]

Haha thanks I’m off to Halfords n Esso

good luck!

 

[VinceB]

Hello! New Bosch coil pack and leads, new mapping sensor new plugs STP cleaner with Italian tune up! Still getting an intermittent yellow triangle every week or so showing the same error codes thankfully no engine warning light so there is some progress stop start has started working new tail gate wiring fixing kit purchased let’s see how I get on if it’s not that are there any other ideas?

 

[steveras57]

Get a used fuel rail/injector set of e-bay and swap it out to see if it makes any difference! i tried two lots of injector cleaner with no change but swapping the injectors cured my issue instantly!

 

[VinceB]

Tailgate wiring fix fitted all lights tailgate lock etc working about a mile into the drive and the warning triangle on again and stop disconnected itself
So now I’ll see if the new injector rail works