I bought this beauty for a bargain last year around September of '16. When I first bought it, it was making the EXACT same knocking sound which sounds very similar to the noise in this video I found on YouTube: https://www.youtube.com/watch?v=gxLh...ature=youtu.be

After driving it for a few days after the purchase; it went away. I did notice the engine was a bit sluggish, and weak. It also needs me to keep a light touch on the throttle when I'm idling with one foot on the break in order to stop it from stalling out sometimes at red lights.

Fast forward to yesterday, 5-31-17, and my car started, and stalled out. This happened multiple times. It would idle somewhat okay, but as soon as I tried applying any acceleration, the car stalled out after moving a foot or two. I was at the store at the time, so instead of trying anything, I called a buddy, and he towed the car to my home. I come back from work today (I got a ride), and I try to start her up, and to my surprise, she starts and actually stays running. I try driving her back and forth in the driveway, and she does so in the way I've grown accustomed to since I've had the car (with the addition of the knocking noise returning anyway) I happened to buy an OBD scanner (OBDLink MX) awhile ago, and recently found it, so I plugged 'er in and gave a scan. I received the following error codes and the brief description of the issue in the order that the app I used (Torque Pro) gives me:

P0131 - Powertrain: 02 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132 - Powertrain: 02 Sensor Circuit High Voltage (Bank 1 Sensor 1)
P0405 - Powertrain: Exhaust Gas Recirculation Sensor "A" Circuit Low
P0138 - Powertrain: 02 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0300 - Powertrain: Random/Multiple Cylinder Misfire Detected
P0404 - Powertrain: Exhaust Gas Recirculation Control Circuit Range/Performance
P1404 - Powertrain: *No Description*

Upon further use of the app, I found that cylinders 2 and 4 are misfiring steadily/continuously while I idle or drive, with cylinders 1 and 6 also misfiring every once in awhile.

I suppose my question is this; If I took this to a garage, would would I be looking at as far as spending? I don't mind spending a bit, because I practically got the car for free. The ONLY thing wrong with it is the engine. Everything else works surprisingly well. (I did have to replace the water pump since I've had the car due to a coolant leak from the radiator a few months after I got it as well as the alternator going out around the same time because of it, but those were the only issues besides the engine sluggishness/stalling.)

With the DTC'* provided, does it sound like something simple? (IE An 1-1.5hrs of labor and maybe $100-$300 for parts like Coils, wires and plugs etc.?) or something more complex? (Major rework. $1000+)

Also, should/can I be driving this car? I haven't been, but I'd like to know.

Thanks in advance guys, I really appreciate it.

I should say, I've tried taking off my EGR Valve to check and see if it was blocked up, and I'm embarrassed to say I couldn't even figure out how to get to the bolts holding it on, in order to remove it! (The bolts are so cramped I can't even get a socket on them)

That being said, I'm not so sure this is something I can do myself since I'm so unfamiliar with it, and I'm VERY ill-equipped when it comes to tools.

I would start with a complete tuneup, since I doubt you know the history of this vehicle.......if there is still a misfire, then you do a coil output check......if it still misfires, then you check compression...if ok, then could be an injector problem....

Once the misfire is corrected, clear the codes and then check to see if any come back....

I forget if cylinders 2 and 4 are on the same coil.

1&4, 2&5, 3&6