Hi there folks. I have a 2007 Cobalt SS/SC. I have ZZP's stage 3 kit, 2.9in pulley, step colder plugs, front mount, zzp intake, 60lb injectors etc along with zzp tune. I noticed that my valve cover gasket was leaking, as well as my intercooler pump wasn't functioning. I replaced both of these today. The spark plug well closest to the drivers side was full of oil, likely due to the leaking gaskets.

We got everything back together, now the car idles extremely rough, like a misfire to the point it will shut off on its own if you don't give it fuel.
We checked the coil packs- all are good.

I checked the connections - all are good.

I reflashed my base tune on the car, it seemed to fix the issue slightly, it doesn't shut off on its own. but still runs extremely rich and idle is still way off.
I'm just wondering if anybody might have any ideas if this could be a tune issue, or something else?

Thanks
Adam

 

While you did do some good troubleshooting, I would start at the base point: when was the last time your cleaned your MAF?

 

Also check/clean your throttle body (just don't move the throttle blade while cleaning just blast it with carb cleaner).

 

Thanks folks - Cleaned the MAF, that's good. Cleaned throttle body, that didn't fix it. We're beginning to think its a CPS sensor or KNOCK sensor. Would these cause issues like I'm seeing?

 

If you reflashed a base tune... I assume that means you have HPTuners. You can scan with the VCM Scanner to see if there are issues with either of those sensors. Generally though, I haven't really even seen a knock sensor cause an issue like this. And a CPS will generally throw codes and, in my experience, it doesn't actually cause this type of issue. More of a hard to impossible to start scenario. Again though. You can check/watch that with the VCM Scanner.