Okay, I just finished putting on my Koni Yellows to compliment my H&R Race springs, but now I seem to have a strange rattle/vibration somewhere near the right front tire. Now, it only rattles at certain speeds, in a certain gear…
2nd gear at 20mph, coasting
3rd gear at 30mph, coasting
4th gear at 40mph, coasting
5th gear at 50mph, coasting
with the gas peddle down, no rattles at all. I can’t find anything loose. Any help? Seems odd to me that it’ll happen every 10mph in another gear.
Check to make sure you tightened all your lug nuts enough! I had a weird vibrating I couldn’t figure out and it only happened when I wasn’t accelerating and it was because two of my lugnuts had fallen off of the front driver’s side tire. I almost freaked when I found out what it was.
You also might want to check your catalytic converter heat shield. The top of my shield rusted around the bolts that hold it together, so the top was rattling at certain rpms. I just pulled it off (the top of the shield, not the cat 
). Might be what’s rattling. Might want to check the rest of the exhaust too just in case it’s something exhaust related. Good luck