2008 Dodge Durango Engine Codes

Here's the page to find the fault code definitions:

https://www.2carpros.com/trouble_codes/obd2/P0400

P0132 - Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 1)
P0456 - EVAP Leak Monitor Small Leak Detected
P1128 - MAP Lower Than Expected

For 132 you'd have to look at the readings on a scanner. Typically if it's staying around 0.8 volts it's related to the fuel / air mixture. If it's over 12 volts the code will be "signal voltage shorted to power", or something like that. If you find something in between it is usually because of wires going to the oxygen sensor are touching as in laying on hot exhaust parts and melting together, or they got caught on something and are rubbing together. Also look for corrosion on the terminals in the connectors.

For the 456 code you can do a visual inspection but most of the time you'll need a smoke machine to find the leak. Look for loose or rusted-off hose clamps and dry-rotted hoses.

I never ran into code 1128 but we talk about this all the time. The Engine Computer constantly compares sensor readings and operating conditions to each other to determine when there's a problem. This code suggests the map readings are within the acceptable range of approximately 0.5 to 4.5 volts, but it is not the correct reading. You'd have to analyze the sensor values on the scanner to determine the cause of this code.