Ok so i have this weird Humming and pulse sounc when i drive at around 3K rpm in any gear but outside 3k Rpm the car seems to run fine i did a small pull and it still pulls strong,
so far i've come to believe its probably a leaky injector anjd of i already know my tps sensor isn't so great being that i have to readjust it every couple of months,

So my symptoms are i get a fair amount of backfire on decel in any gear, m y Mileage ona full tank whiel not driivng relatively hard is roughly 220miles per the whole tank which is very low, and that i was diagnosing the car today and if i rev at idle to over 2500-3000rpm i get small tiny backfire pulses at idle when i hold it at 3K rpm,

Any extra insight would be helpful but i think its the injectors that are leaking , btw i have a S5 GTUS NA, on 460cc injectors that was cleaned and flow tested 2 and a half years ago, about that time its been a while i can't remember the exact time i had them cleaned.
thanks