Why would a 2000 Dodge Stratus 2.4 L be sputtering and knocking and driving but hard at higher mph?

Well your question is not clear because of the gramatical errors, but I believe you are asking about knocking and sputtering at slow speeds but consistent and good at higher speeds....well here is my answer to you. The higher speed consistency compared to the lower sputter is probably one of two things or a combination of both or even a third. One, you have a rough idle which can be caused by: bad fuel injectors, bad ECU, or wrong or bad spark plugs. I would recommend that you disconnect your battery for 30 seconds to wipe the ECU and then try to start and drive the car again. If this does not work, then you will need to have a repair shop look at your fuel delivery (including fuel filter, injectors, and even your spark plgs). Your bad combustion can be any of the above and that would explain the sputtering at slow speeds. Now the second problem could be that your transmission is slipping gears and causing the vehicle to sputter and try to get in the correct gear until you get to a higher speed and a gear that is not malfunctioning. The third possible problem is that you Cam Gears are not properly functioning. If you have the 2.4 you have a dual overhead and the 2.7 or 3.0 is SOHC (if i am not mistaken). A DOHC means that you have one Cam opening and shutting for the intake of air while the other opens and shuts for the exhaust. One Cam can be malfunctioning and that is effecting the other which would cause rough idle and sputtering as well. That is all I have for you and any questions can be directed to tony_velociti@yahoo.com Thanks.

Answer

I had a same problem, mine was electrical. You should get a computer test done if your check engine light is on BEFORE YOU DISCONNECT YOUR BATTERY. Otherwise the computer wont test until so many miles driven. my test was Cylinder #2 misfire so i put on new wires and plugs, that did not fix it. I did a test with the brand new spark wires. I pulled the wire on the #2 cylinder (the other end of the spark wire was still on the COIL) and stuck a long peice of copper speaker wire in it. Then I took the other end of speaker wire to the frame and there was hardly no spark at all. The same test on another cylinder however produced plenty of spark. This proved to me that the problem was in the spark and it was not the wire or the plugs because i just changed them ($30.00) It had to be the COIL PACK, so I got one from autozone ($75.00) put it on and fixed the car. CAUTION: The test is dangerous you should us some kind of rubber insulator when handling the live wire and you also want someone else to turn the car over and off.

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