Heavy Surge, Hesitation, Stumble

[Biggins240sx]

Alright. So recently I've tackled reduing the timing in my car. Got it running great. Its been about a week now. So I was driving yesterday to go help work on another car, My car started to hesitate. I was driving normally for about 10 mins and around 3000rpms I started surging. My rpms just started jumping. So I researched all this. I already checked my tps. But I just would like to know which things i should check. Maf being one. What else?

[amanoma]

im not an expert but i searched about it cuz i had same problem, check or clean aicv and check vacuum leaks.
i cleaned my maf and its fine now

[Biggins240sx]

To update on this. I Had pulled many codes and checked all of them. It came down to the knock sensor. But yet I rechecked the harness and found a loose connection.