2006 Cobalt SS 2.4L Automatic Transmission

CEL came on and T/C Off Light illuminated on my dash. It shifts hard, and when I come to a stop, it idles around 700 rpm, the lights on the dash flicker with the engine, and it barely sounds like it's going to stay running. Pulled P0171 System Too Lean, and a Random Misfire. It's 24 degrees out today. Also, it sounds like I have a leak in my exhaust manifold or down pipe. Replacing the Mass Airflow Sensor is the step after inspecting gaskets, retightening bolts, and checking for leaks in my intake.

 

Exhaust leak is causing the P0171. i doubt the misfire is related, it's probably something spark related.

 

Okay so update to this thread:

I went out to my car yesterday to visually inspect my exhaust in daylight.
My piping snapped completely off. The break happened just on the side of the downpipe gasket closest to my muffler. Completely separated. Car is ridiculously loud, sounds like a drag car. My exhaust guy is on vacation until Wednesday, December 26th, so there's not too much I can do besides try to avoid driving.. I went from around 27 mpg city/ 34 mpg highway to about 14 mpg city, so I need to get this fixed ASAP!

I was thinking about having a new cat-less down pipe, then go to a Y-Pipe, and have another 2.5" exhaust with another Magnaflow Muffler and stock SS tip, then cut a space in the plastic protector, and hang it all up.

 

Dual exhaust?

 

Its broken off at the flex pipe section? I had the same thing happen to me. Same thing happened to my friends 05 SS supercharged model.
I took it as a prompt to just replace it with larger downpipe and high flow cat that I always wanted to get instead.

 

Yeah, see Kansas doesn't have emissions testing.. Yet. That being said, I like to rock the "no cat so when I floor it a little black smoke comes out". It was about time to redo my exhaust anyway, I was on stock SS 2.5" piping with 114k on the car, 64k on the motor. Rusty exhaust piping isn't any fun. Plus, it's an excuse to drop a little more money in.

 

Kansas isn't too bad. I love how I can rock a 3" straight exhaust without any harrasment.

 

If you do dual exhaust with our 2.4, have the downpipe before the split 2.5in, then after the split have both pipes 2.25in. You want to maintain exhaust velocity and even flows. It's better to be slightly too small than too big. Unless you plan on going crazy with a 400+hp huge turbo and what not, then maybe a 2.5in system all the way through is justified. Dual exhaust on this car is difficult, there is no place for a Y pipe, you have to do it custom and it has to split around the rear axle. No room otherwise. Unless you want one sides piping lower than the others... which is extremely tacky.

 

Are you goin to KSC2K13 this spring?

Yeah, I could look into dropping the diameter, at least after the y-pipe. 2.5" until a split into 2-2" pipes might possibly work. I have a good welder who works for cheap, so I'm in a good position to see what's up.

 

Don't dual it