Hello there! Recently my cars been acting strange. It is a 2001 Sedan 2.4. We first noticed that when on the brakes (and sometimes in park) the car would start thumping. Like you could feel it in the seat. And then sometimes the car would jerk a tiny bit when accelerating. The check engine light had come on for the fuel cap so that was an easy fix. But my boyfriends dad thought the other problem was spark plugs. It wasn't because they were brand new but they changed them anyways...
After that the thumping had started to stop and I've only noticed it once since then. But the check engine light came back on and now when we are stopped at a light or making a turn the car struggles to get passed 10-20 mph and you have to let off the gas to let it go a little on its own otherwise the check engine light starts flashing and then everything's normal. And if we go on the freeway and try to pass 50-55 mph the car starts jerking and sometimes (but not usually) the light flashes and then it drives normal.
I went to autozone and got these codes P0303 and P0442. I'm not sure what anything really means and it doesn't feel like its safe to keep driving my car. Any help, even a little, is greatly appreciated

 

I'm far from being an expert on this, and my Sebring has the 2.7L engine...but, I have a chart that lists the 'codes' you might get when
doing a system scan. It's a "PDF" file - is you want I can send it to you
in an email.

 

That would be great

 

P 0303 is a cylinder 3 misfire. Replace the spark plug wires and/or the coil pack if you've already replaced all the spark plugs. If this 2.4 is the same design as the 2.4 used in Neons and PT Cruisers, the ignition system is actually relatively simple. It's made of three basic parts. Replacing all three at one point in the vehicle's life is actually recommended. I've replaced my coilpack in my Neon four times since owning it, and plug wires twice. You should replace the wires every other plug change.

P 0422 is a small leak in the evap system. That might be related to your fuel cap, and wouldn't cause this kind of problem.

If a misfire is bad enough, it would create that kind of issue:

 

Thank you. That is probably what we will try next

 

If you send me your email address, I'll get that file out to you today.

Mine is luke892@yahoo.com

 

Luke. No need to broadcast your email address. The forum here has a system for sending private messages that members can use if they need to.

As for your list of error codes, these are widely available on the internet. All cars nowadays utilize a common on-board-diagnostics system (OBD-II) and if you google that you'll find tons of information including listings of the codes and how to fix them.

 

rgr that...just trying to be of assistance & contribute