My 09 cobalt ss/tc is running rough and throwing several codes and am having trouble finding the cause. I have replaced the map sensors before, But it had thrown different codes that led me to it so im a little lost!! any help would be greatly appreciated
Codes are:
P0451 - Evap emission control system
P0507 -
P2187
P0236

 

Mine was throwing the P10010 code, I think. My uncle has the scanner but I don’t have one yet. Based on that, my camshaft solenoids were not working. I have replaced them but even now, the car still isn’t starting without a jump, and it won’t run for long either. Maybe we have a similar problem?

 

Completely different in your situation. Your car needing to be jumped, and not running long sounds like a battery/alternator or charging issue. Your cam solenoid code/codes, would not have anything to do with that. To help solve your issue you can buy a scanner that can read your codes and check your charging system, and others for pretty reasonable prices. You may want to look into that.

 

Some of these codes have ben pretty common the P0236 and P2187 have happened quite a bit. I did quick search here on the forums, and then looked up the codes to verify some things. Most of points you having some type of vacuum leak. Some info below.

P2187 - Bank 1 lean at idle - You could actually be running lean at idle. Check your AFR at idle. Your idle should around 14.7, it may bounce a little up and little down, that's normal. If you go to read your AFR and it is stuck at 14.7 and doesn't move you more than likely have a bad o2 sensor. If it reads normal, you may have a vacuum leak.

P0507 - High Idle - I had to search this one. The one thing that stand out to me is that it can be caused by a vacuum leak.

• The throttle actuator control (TAC) motor is controlled by the powertrain control module (PCM). The DC motor located in the throttle body drives the throttle plate. In order to decrease idle speed, the PCM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the PCM commands the throttle plate open allowing more air to pass the throttle plate. If the actual idle RPM does not match the desired idle RPM within a calibrated time, this DTC sets.

Conditions for Setting the DTC

• The actual idle speed is approximately 100 RPM greater than the desired idle speed.
• The above condition is present for 10 seconds

Inspect for the following conditions:

• Vacuum leaks
• Excessive deposits in the throttle body
• A faulty positive crankcase ventilation (PCV) valve
• A skewed manifold absolute pressure (MAP) sensor
  

P0236 - This code has come up many times when there is an issue with the MAP sensor on the lower charge pipe. Could be a bad sensor, faulty wiring, a leak. Another thing that stands out on this is vacuum lines. The O ring on the MAP sensor could be, torn, cut... ect.

Conditions for Setting the DTC

• ​​​​​​​​​​​​​​When conditions to set P0236 are present the PCM ignores actual manifold pressure readings and uses a inferred or assumed manifold pressure, limits the amount of fuel and dynamic injection timing allowed. The PCM enters what is called failure mode engine management (FMEM) and is most noticeable by a lack of power.
• ​​​​​​​Inspect for the following conditions:
• ​​​​​​​​​​​​​​​​​​​​​Vacuum supply
• Pinched, collapsed, or broken vacuum lines.

​​​​​​​P0451 Evap Emission System Pressure Sensor Performance - This one is probably completely separate from the others.

​​​​​​​Thing to look for:

• Defective EVAP pressure sensor
• Loose or missing fuel cap
• Clogged fuel tank pressure relief valve
• Broken, collapsed, or burned EVAP hoses/lines
• Cracked or broken charcoal canister

​​​​​​​​​​​​​​

 

Thanks I will check into those things, really appreciate you reaching out with the info!!