Dtc p0405 & p0406 these codes came up when i checked my dtc and would like to know what the codes are and what is needed to correct the problem. any help would be appreciated. I changed the oil and the engine light still stays on.

Is the check engine light on ? Any DTC'S - diagnostic trouble codes stored ? If any of these are true , light on or code's stored monitors will not set . Too set all monitors you do a drive cycle . A very specific way of driving your vehicle .

http://www.lyberty.com/car/drive-cycle.html

DTC P0405 Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage. Need to replace.

You need to diagnose the EGR System
Not replace parts in hope of getting it right
Codes only indicate an Emissions Malfunction
or Fault, thus the code
Codes & trouble charts are used to then component test
Google the code & study the problem
There are many EGR Codes--- study yours ,as it pertains
to your vehicle & engine package
Try You Tube Video-- to get a basic of what egr system is & does

What code ? are a few different ones for EGR valve > Low & high circuit voltage , testing circuits , PCM testing etc.... no code tells you to replace the EGR valve without testing . Your best bet , take it to a qualified repair shop.
DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient
DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit
DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance
DTC P0405 Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage

Feb 7/11 - P0405

Jan 11/11 - P0336 - P0326

Dec 28/10 - P0217 - P0218 - P0163 - P0230 - P0231 - P0232

Dec 9/10 - Trouble Codes: P0170 - P0173 - P0162 - P0154 - P0142

Dec 6/10 - More DTC articles: P0157 - P0158 - P0160 - P0200

Nov 30/10 - DTC articles posted: P0505 - P0156

Nov 18/10 - More new articles: P0143 - P0144 - P0146 - P0147 - P0152

Nov 12/10 - P0120 - Throttle Position Sensor/Switch A Circuit Malfunction

Nov 11/10 - ECT Circuit Codes: P0116 - P0117

Nov 10/10 - P0111 - IAT Circuit Range/Performance Problem

Nov 7/10 - P0110 - Intake Air Temperature Circuit Malfunction

Nov 6/10 - P0108 - Manifold Absolute Pressure/Barometric Pressure Circuit High Input

Oct 21/10 - P0216 Injection Timing Control Circuit Malfunction

Sept 11/10 - Knock Sensor DTCs: P0327 P0332

Mar 15/10 - P0607 Control Module Performance Code

Mar 4/10 - P0606 PCM Processor Fault DTC

Feb 10/10 - New ECT Sensor article

Feb 9/10 - P0012 & P0022 - Camshaft Position - Timing Over-Retarded

Feb 2/10 - P0115 - Engine Coolant Temperature Circuit Malfunction DTC

Jan 19/10 - P0105 - MAP/Barometric Pressure Circuit Malfunction

DTC P0406 Exhaust Gas Recirculation Sensor A Circuit High.

You in fact do, need to replace the EGR valve. P0406 is actually EGR position sensor high code. Which means the PCM recieved a egr position sensor signal greater than 4.89 volts. For some reason the the egr on the 05 minivan had a high failure rate.

The best way to get at the lower bolt after you remove the upper bolt and the two 8mm tube screws, pry the valve rearward. This allows you to get a socket on the lower bolt.

Hope helps (remember to rate and comment this).

try swapping #1 injector with another injector to see if the code jumps to another cylinder. maybe possible that the injector maybe clogged cause a misfire code. best to change with one in the front. dont know what p0405 is off hand. is it an evap code? try swapping the injectors first the clear the code and see what comes back

According to my OBD2 reader manual a P0406 code means the Exhaust Recirculation Gas sensor is in fault. So it means that you have a problem with your EGR valve and/or sensor. So just change them, but be warned, even jobber model go for over 100$ normally, so might be an idea to scrounge around the scrap yards.

they needed to replace my IAC module. (Idle Air Control)
covered under warranty cost me 50.00 deductible Good luck