Help: hard vibration between 45 and 50

[Demon I Am]

Did not notice the issue until coming home last night. Between 44-50 I was getting a hard vibration and echo sound, that reminded me of having delrin motor mounts.

The vibration feels and sounds like it's coming from the driver's front side. It would also happen randomly while driving for a few seconds.

No noticeable loss of performance. No check engine lights.

I have checked the tire and the lug nuts they both look fine.

This morning I opened the hood, and found an exhaust clamp bolt? It was dangling behind the O2 sensor. I was able to reach in and plucked it out.

Wondering if a have some sort of exhaust failure that could be running the frame? Not sure what exactly that bolt does

[Demon I Am]

Ok so I don't think the site is letting me upload pics from my phone. There is a very large metal clamp, just after the first o2 sensor. There was a rusty 3 inch bolt wedged between this clamp and the subframe.I successfully removed the bolt, and discovered that some part of the threaded end had sheared off.
I took the car for a drive and can no longer duplicate the noise.

Anyone know if that clamp and bolt are important, and how quickly should I hurry to fix this?

[Demon I Am]

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[— kung fu jesus —]

Trying to remember...but I *think* it secures the exhaust to the car. It could be whatever caused the vibration sheared that bolt.

Check the driveline to see if anything hung up in the driveshaft or axles (debris, grocery bag, etc.).

Maybe you lost a wheel weight. Maybe rotate the wheels to see if the vibration changes?

[Demon I Am]

Taking a look under the car this weekend.

[★ revlimiter ★]

I'm betting on wheel balance or mounting. That's what it usually is for my cars.

[Demon I Am]

Symptoms totally gone after pulling that bolt, and over driven the piss out of the car today. Guess that one bolt was causing the bs

[Airbrush1]

My 2000 was a Cali emissions car, and had a similar brace/clamp up there. It was a huge pain in the butt to remove when I put my header in. I do imagine that it being wedged in there would cause an issue. As long as you don't hear any leaks or have any other issues, I'd leave it alone until you get a chance to mess with it at your leisure.

[NCGreasemonkey]

There is a exhaust brace that mounts the exhaust to one of the bolts that attach the tranny and engine. When I installed my engine mounts I removed it because it was broke and in the way.

Shouldn't be a worry. Just next time you have it in the air whip the rest of the bracket off the tranny bolt.

[Demon I Am]

Sweet. Nothing like a cheap fix