Don’t know if this is the right place to post. My son is in the military stationed in ft Bragg NC he’s been without a vehicle for 2 years, he recently saved up some $ to get a vehicle just something to get him around base, I found an 01 4Runner 200k runs great, brought it home to get it ready to drive out to NC three days later I took it to get emissions test and it started knocking nothing crazy like a cam or crank to me it sounds like a lifter or valve, I’m looking for someone who has the adjustment tools or someone willing to help me with it, it still runs good with the knock any help would be greatly appreciated