Ok this one really stumped me. My sister has a d16 civic with a fresh engine with only 15000 miles on the build. The mods are stage 1 cam, and adjustable cam shaft, rod bolts and a good polish. Nothing major. The chassis has about 180,000 miles on it. Well this weekend the engine was sputtering real bad. I popped open the hood and though, hmm, bad timing belt, I just changed it wtf. But no as I dug in there it was the harmonic balancer crank pulley damper. It was wobbling, I got underneath the car was able to feel some play. Took a little trip to pepboys, bought the part and 2 hours later had it in. Turned on the car again and the belt has some play. I was like, aw crap, I should've changed the drive belt too. Got another belt and now the engine purrs and is solid on idle.

humm...never heard of that but good info

This is not unheard of. It is really common on GM cars. I am a tech and see it alot more than you would think. A bad crank pully/ balancer can even cause a missfire that can set a check engine light. this is not to common with Hondas though.