I'm hearing a tap-tap-tapping noise, really quite loud, from the injector area - not valve noise. I'm also seeing the car run lean occasionally on normal acceleration and hesitate on throttle tip-in sometimes. I thought it was detonation but I'm running 2 points above the minimum and timing is within stock specs.

Is there any way to check injectors without pulling them off? It's for a JDM B16A.

 

Pulling the injectors is not hard. Just undo those little clips on eash side then pop the injectors out. I would do that first, make sure they are clean and what not. Then try and run some higher octane gas just to make sure.