Codes P0049, P0455, P0449, P0102, P0113 and P0068, RPM idle keeps shutting down?

CR178032

MEMBER
2007 CHEVROLET MALIBU
3.5L
V6
AUTOMATIC
160,000 MILES

My rpm idle keeps dropping down to 0 when I come to a stop as it is supposed to just hover not drop down. Then I'll have to be able to cut my car off then on to be able to drive the car again. When I am going at a decent pace, my car goes into energy power reduced mode. My codes on my engine light are p0049, p0455, p0449, p0102, p0113, p0068. I'm trying to find the parts to fix the problem.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,192 POSTS

Hi,

We have codes for several different issues. For example, the air intake temp sensor, mass air flow sensor, throttle actuator, and so on. The one that sticks out to me is P0449 which indicates a large EVAP leak related to the vent solenoid control circuit. If we have a large leak, it could be setting the other codes.

Another concern is the P0049. It shouldn't exist on this vehicle. It is related to an issue with either a turbo or supercharger charger which isn't listed for this vehicle.

By chance, do you have a live data scan tool? If you do, could you let me know the short-term fuel trims?

Also, here is a link that explains how to check for vacuum leaks. See if any are present.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

The P0449 indicates a large lean in the EVAP system, specifically, the canister purge valve. This component is located above the fuel tank. See pic 1.

Because accessing the components for inspection is a nightmare, what I recommend is to have the EVAP system smoke tested. Basically, smoke is injected into the system at a very low pressure. If there is a leak, the smoke will come out at that point.

Because this is a large leak, inspect the fuel cap, filler tube, or anything you can see around the fuel tank.

Let me know.

Joe

See pic below.

Image (Click to make bigger)