Does D4f engine overfuel from factory or could it be tuned?

[Brandon Dommett]

Hello ,

I bought my 1.2 16v bone stock in august 2021 and around may 2022 has a mid/rear catback exhaust installed , after some time it has decided to give itself some small pops with the occasional bigger bang which can be audibly heard.(the car on occasion may also give off almost an egg smell). Does anyone know if these engines run a bit rich from the factory or it has been tampered with?

I have attached a small clip with how it sounds (with the car warm of course)

Thanks in advance

 

[hopgop1]

Probably over-fuelling. On a sport I'd be looking at injectors or lambda. Any codes to go off?

 

[Brandon Dommett]

Has no codes and runs like a dream , once it warms up starts to do those. Not exactly a problem just wondered if it's common since after some google searches couldn't find much about them over fueling from factory

 

[Martin_172]

mine never used to do that back in the day

 

[Brandon Dommett]

I can get it to do it mainly at 3k rpm by throttling on and off quickly but even at lower RPM around 1700 just letting off throttle it will do it, shouldn't do any damage really may just be it's the older engine style

 

[Chrisgti6]

An egg smell indicates a knackered cat doesn't it?

 

[Brandon Dommett]

An egg smell indicates a knackered cat doesn't it?

The smell will come and go with no pattern to it , it also passed it's MOT in August with no issues with gasses