Chrysler Cirrus 2000

I own a cirrus 2000 which lately have been giving me trouble. I took it to a mechanic for tune up and ended up having alot of issues. At the moment I am having a lot of rattle or hard driving. The car shakes alot and recently I took it for a diagnostic and the result was P0303 and P0305 and vaccum leak. What causes this problem and how can I get it fixed?

Get the vacuum leak fixed first.

How many miles?
What year?
What engine?
Check engine light on?
Check engine light flashing?

There are many possible causes for p0303 and 0305. Those are misfire codes, by the way.
Misfire #3 cylinder
Misfire #5 cylinder

Let me add two more questions. Is all scheduled maintenance up to date? What exactly was done during this tune-up?

You did not have these problems going in but have them coming out? You didn’t take it to a mechanic, you took it to a moron.

If it is the 2.7L V6, consider the car trash. Any other engine and you need some basic work and a tuneup you can do yourself. First, you will need to check all the vacuum lines and you might just replace them as some small holes/splits in these are hard to find. These lines are cheap and you can buy sections from parts stores and cut them to size.

If its a gen III 2,7, there is nothing wrong with it. Chrysler took the time to redesign it to eliminate its weaknesses instead of just abandoning it altogether. They took the Toyota approach of improving instead of the GM approach of abandoning on this one.