My 2006 mustang has the 4.0 in it and is throwing the code P0108 which is the map sensor I've heard its on the egr valve

SOURCE: 2006 Dodge Grand Caravan - EGR code

I replaced the EGR Valve ($80 after tax), problem solved, vanruns great now. Now my problem is that I can't get the light to turn off.

SOURCE: 94 Automatic Geo Metro 3 Cyl. Map Sensor - EGR Valve

Unfortunately, both of these items are equally important and repairs can't normally be avoided by taking care of your car.

Your MAP (Mass Air Pressure) Sensor measures intake manifold vacuum pressure to help control the air and fuel mixture and timing. It contains a pressure-sensitive element that connects to an electronic circuit, generating a signal that changes with pressure changes in the manifold.

Your EGR (Exhaust Gas Recirculation) valve recirculates exhaust gases through the intake manifold to be burned again, cooling peak combustion temperature. Dilutes the air and fuel mixture to keep the nitrogen oxide emissions within breathable limits. And yes, it could very well be that the EGR solenoid that is causing the issue.

Both units effect your vehicle's fuel/air mixture. This is important because your vehicle running lean/rich can cause "snowball" problems. For example, a faulty EGR can cause the vehicle to run rich/lean. If not repaired, in time, the exhaust caused by the wrong rich/lean fuel mixture can damage the O2 sensors and/or catalytic converter.

If I had to pick, I'd start with your MAP Sensor. One guess I would have is that your MAP Sensor failed and made your vehicle start burning the wrong fuel/air mixture. Assuming I'm right, this could have damaged the EGR Valve. So, I see no reason to replace the EGR Valve alone, just so it too can be damaged by the poor fuel/air mixture caused by the still-faulty MAP Sensor. If your lucky, you may see the faulty EGR code disappear once your MAP Sensor is replaced.

Hope this helps and good luck!

SOURCE: Check Engine code P1409

clean the egr valve port on intake use piece of clothes rack clean the built up carbon on inside of port.

SOURCE: Cobalt not running at low rpm.......

All are possibilities but EGR valve makes the most sense. It's famous for causing poor idling and/or stalling at low RPMS. Best of luck.
Greg

SOURCE: code p0406 says that the reading is high at EGR

They are usually one in the same if it has three or more wires going to it.

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