2006 Aveo

[DianaG]

Hi, I've recently purchased a 2006 aveo, and I get these codes p0 300, p0 301, p0 304. I've had my spark plugs and wires replaced with new ones along with ignition coil and crank sensor replacement. The car seems to run fine, no hesitancy or noises or shaking. I am looking for some advice on what else can be checked to be causing this problem. Also the check engine light is constant (stays on all the time when started). Thanks!

[RicochetRandy]

Valve gasket, vacuum, valves/lifters.
Try disconnecting the negative battery cable for a minute or two and see if that clears them.

[DianaG]

Thanks will give that a try and let you know, I just got it and it drives so good but this is a discouraging start to not be able to get it registered!

[petrified.rabbit]

Being the the 1 and 4 cylinders share a coil, I would still suspect the coil. It is possible to get a bad one new if you get aftermarket especially. The thing about ignition parts, like the wires, is plugging and unplugging them in tends to cause damage as well. I am not saying they are one time use, but you can fray the wires and crimp connections if you do not remove them carefully. So check that nothing is damaged. I tell people to do this at night, take the engine cover off, start the car, and mist water on the system. Don't touch anything. But 99% of the time whatever starts shooting sparks is what is broken. If no sparks are coming out, then check the spark plug wells for oil, if they are dry, plugs are gapped properly (again if you remove the plugs be careful with the wires). Then I would switch out the coil pack.

[avguy]

Misfire on 2 cylinders without any noticable performance problem is puzzling.
Assuming the CEL wasn't on when you bought it, how many miles did you drive before it came on? It sounds like you had the work done at a shop. If so, did you ask specifically for all of those things to be done, or was it just someone hanging on parts? A good mechanic will diagnose, figure out what's wrong, and then replace the part that's bad. And along the lines of what Rabbit said above, it may even be possible you were billed for a coil that was never installed.

[DianaG]

Finally got these three codes to turn off by replacing the manifold gasket, now I am getting a PO315, any ideas what I do now?

[DianaG]

Finally got these three codes to turn off by replacing the manifold gasket, now I am getting a PO315, any ideas what I do now?

Upon doing some research, I think what I need is a reset with a Tech-2 scanner (fingers crossed) Thanks so much to all that chimed in with their knowledge and expertise, it is much appreciated

[DianaG]

Back again, I took it to a different mechanic and he tried the "relearn" procedure The CEL will go off but then when the key is put in the switch it goes on again. He suggested that I put the original crank sensor back in the car but I was told that one is cracked so how do I get the car to learn the cps? Do I need to put an ac/delco crank sensor instead of what I bought from autozone? Again, help is much needed and appreciated. ( He did check the fuses for the computer and all are ok)

[thehunterooo]

Disconnect the battery for about a hour or so, then reconnect it, turn on the car and see what happens.

[DianaG]

Disconnect the battery for about a hour or so, then reconnect it, turn on the car and see what happens.

That did not work, I took it to another mechanic and he tried to do the relearn and the check engine light will clear only to come back on again as soon as the key is put in. He put in the original crank sensor and got the same exact reading as with the new one. He unhooked the battery and the same thing happened, the check engine clears but comes right back when you insert the key.

He said he is stumped, thinks it might need to be reflashed but is unsure. Does anyone have any experience with anything like this? If I have to have it reflashed how much am I looking at?