Car making loud noises!

Ok heres the deal, this weekend i took my car to atlanta by the way it got there on 1 tank of gas!...Well heres the problem, on the way home with about 200miles left i decided to pull off and take a little nap the car was doing fine, well after my nap 1:30 min later i started my car and it started making a loud clanking noise, i checked the oil and its not the oil i just had it changed and i also had a tune up, what could it be!! it sound like its coming from the engine but i was thinking it could be the converter. any help will we appreciated!

Absolutely no way to tell you. Could be anything.

try to be a little more descriptive

Poke the catylitic converter with a stick a few times and listen if you can hear anything rattling around in there.

If it growls at you, stop poking it; they usually don't like to be poked. It could also be some sort of mechanical part, perhaps the muffler bearings.

Any reason you suspect the convertor? Your sound has to be a moving part, I would think, unless it is a heat shield rattle or something. The only external moving parts are belt driven. Take a look there while it is running, and see if the belt tensioner is jumping around, or any pulleys seem to be wobbling. That would be the first step. Let us know.

ok i started the engine and looked, the engine shakes really bad and also when i look under my car the whole exhaust is shaking violently, also it makes the noise when its in idle the it makes the noise more frequent and louder when i press on the gas it goes from tink tink tink tink to tinktinktinktinktink

Might have lost a rocker arm? Vacuum test needed. Runs sluggish? Sounds like a dead cylinder. Need to find out why.

Make sure all the plug wires are pushed on all the way. It may be missing if the mech didn't get the wires on tight after the tune-up. I think your noise might just be from the shake of the misfire, not the cause, but we gotta figure it out.