Title says it all really! S13 200SX CA18DET, completely stock
I changed the air filter as part of a basic service, and it's just ran horrendously ever since
Idle seems fine
So at lower speeds and in lower gears, above about 3000 rpm the car starts stuttering and feels like it's about to stall, has pretty much no power
In 3rd gear and above, it stops doing that although the power seems to dip in and out as I'm accelerating
By 4th and 5th gear going above 40-50mph I don't have any issues, boost seems okay even when dropping down gears etc
I'm presuming I dislodged something somehow when opening the airbox but I don't know what! I've checked around that area but can't see any connectors or lines loose
Any help would be super ultra appreciated