Thanks to Texas Grease Monkey for all prior help and, most likely with this problem. I have a 95 civic 1.5L SOHC that has a fluttering noise (that I think could be coming from the valves or pistons hitting something) that is faint and pretty much in every gear with hard acceleration. Easily heard in 5th gear when climbing a slow grade. The flutter doesn't always sound even, but sometimes has some louder sounds in there as well. Is this engine ping or something worse? No other problems with the car. I did replace the timing belt 10K ago and I think this noise was there before I did that. Thanks in advance!
Regards,
Steve

It is likely engine ping/knock. Try putting in half high test and half regular gasoline. If the problem goes away, it's engine knock. Then, try going to the next colder NGK spark plug and retarding the timing slightly (mark the distributor's mount and rotate the distributor .25 inch to the right). See if your situation sounds like what I experienced:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-4.html#post324106

Lean burn tends to produce engine ping.

Well, TxGreaseMonkey has done it again! I filled up with 93 octane fuel and no more noise! Just one day of driving, but I'm sure I would have heard at least a bit (I have nothing else to listen to because my radio is broken, but don't worry about that one TxGM, I can handle that!). Anyway, can I put the other spark plugs you mentioned in so that I can run the cheapo gas in my car? It only has 108 horses and I can't feel good about buying premium gas for a POS engine. Does the pinging harm anything if I ignore it? Thanks again!
Regards,
Steve

Install colder plugs, retard the timing slightly, and then you will be able to get by using 87 octane gasoline. Over time, engine knock can be very serious--I wouldn't risk it, since the solution is so simple and inexpensive.