1.6 16v chugging, reasons?

[Rory connolly]

i have a 1.6 16v petrol leon and recently the cars been chugging when idle only first but now when driving too until rpm is built up high
there’s also a slight popping noise coming from the exhaust but not as noticeable as the likes of a pop and bang map
spark plugs were changed 5 months ago roughly 5000 miles ago but to be fair they were cheap as chips so might be poor quality
was wondering if anyone has had any experience with this sort of problem and what was the reason for it?
have tried searching it up but everything’s very general and i can’t seem to get a good answer

 

[Rich.T]

It maybe worth sticking a set of decent quality and correctly gapped plugs in and go from there.

 

[MoToJoJo]

Maybe MAF but go with the spark plugs first