Hi, I recently bought a 2004 Mazda 2 with the 1.4L petrol engine with only 27k miles.

Now after servicing it and changing the spark plugs twice I am now having running issues including getting an engine light with the code P0171 running lean.

After coming across this issue I have replaced both lamda sensors and still have the issue it's seems to be a lack of fuel, but now after running it for a couple days driving it to and from work it is now struggling with throttle response in first gear with my foot flat to the ground and the engine is sort of popping almost like the engine is back firing.

Any help is needed as both me and my dad are very stuck with what the issue could be.