Rough idle and indecisive P0300 code
 

Hello all, I have a 2003 Cavalier Ls with the Ecotec F Vin motor, 4 door, 180,000 miles, I am the second owner. So I was driving one day and when I stopped at a red light the motor started idling rough and then immediately died. I cranked and was able to get home without any other issues. Driving it the next day I noticed it fluttered (idled rough when stopped) except when I was driving, as long as I am moving I am fine, but it will die every once in a while when stopped. I replaced the spark plugs, ignition coil pack and control module, air intake sensor, map sensor, throttle position sensor, and idle air control valve. The car ran great for a week, I drove it about 450-550 miles during this time, but periodically it would have a much fainter rough idle and it did die on me once when I was parked without any leading indicator that it was going to die. Before I replaced the parts, I cranked it one time and it revved high and gave the P0300 code, so I changed out the parts and this went away, I did a battery reset. I was driving home today and when I went from park to drive, the motor revved high and then gave the P0300 code, when it did this the cabin filled with the aroma of gas and this has never happened or I may have never noticed. I stopped the car, went, and checked the connections on the parts I had replaced thinking maybe I missed a clip, but everything was connected. I cranked it and the code was gone, it drove great all the 1/2 mile home, even when stopped. Has anyone dealt with this before, any suggestions? I am wondering if this could be a blocked purge valve canister or timing chain-related. The thing that I do not understand is why it gave the code when I went from park to drive?

Car Dies, sometimes, P0300
 

Hello all, trying again. So my has this weird problem where it dies within a few minutes of starting or will throw a P0300 sporadically. It is a 2003 Cavalier LS, F vin 4 door, automatic. It has done this in the past and each time I would just replace the ignition coil pack and control module and it would be good to go, but not this time. I have replaced the spark plugs, ignition coil pack and control module, idle air control valve, MAP sensor, throttle position sensor, purge valve, and the air charge temperature sensor. Does anyone have suggestions on what it might be, I am thinking it may be timing but I am not sure.

Getting closer
 

Hello all,

Sorry to make another post, but I am still chasing the issue on my 2003 Cavalier LS with the 2.2 Ecotec, 4-door automatic. So the car will just die when idling. For a while, it would complete the ignition cycle and then start idling rough and would die sometimes while idling rough. Replaced ignition coil pack, ignition control module, ignition switch, spark plugs, MAP sensor, idle air control valve, throttle position sensor, and air charge sensor, and it has improved the idle, but now it will just go from normal healthy idea to suddenly dyeing with no indication. When it was idling rough it would give a P0300, but it does not do this anymore, it just dies. I am thinking that it is the alternator, as it is drenched with oil. I am planning on replacing the alternator and the crankshaft cover seal, which is where I think the oil is coming from. I wanted to ask, does anyone know the signs of an alternator that is cutting out on a cavalier? The battery with the car off is 12.3 volts and then 14.1 when running, so I initially thought it was ok, and it was replaced 2-3 years ago. But it dies 10 seconds after turning the AC on, which leads me to think the extra load caused the system to drop enough for the car to die, maybe not an entirely bad alternator but one that is cutting out. Also, does anyone have recommendations on where a passenger-side oil leak on the motor is coming from?

Now I will say that it will die a lot of the time by simply shifting from park to drive or reverse, which has led me to question the torque converter clutch. Does anyone have experience with this and some potential recommendations on diagnosing? I think I got the other cavalier running, but I broke the nipple to the air resonator that connects the resonator to the valve cover. This has happened before so I replaced it, but does anyone know of a good fix for this, as they are just made poorly? I am thinking of a small brass connector that is just slightly larger than the hole that will allow for a tight, sustainable connection. Does anyone know what size this hole is or maybe a good fix recommendation?

Thanks all

For the nipple, use some JB Weld on it and it won't go anywhere.

Thank you, I used Epoxy and it has held even in the post-apocalyptic road conditions in Atlanta. Your answer makes me feel justified in my solution, so thank you!

Thank you Pierregirard, I am going to look at these over the holiday weekend. I did not even think of checking the injectors.