Two codes coming up on car even after fixing alot on car now need to figure out low cost ways to fix P0744 & P0722 code issues spent 1,800 on car & have spent 1,400 already in parts & labor.

SOURCE: code P1400 on a 1997 nissan maxima. help car wont pass inspection

P1400 on your vehicle is described as :Differential Pressure Feedback EGR Circuit Low Input You either need a new DPFE valve, or a new EGR valve. Both can be tested for functionality before replacing them both. EGR valve is more likely I think. Cleaning it may not improve its performance, but its worth a try. Also check the vacuum lines between the DPFE and EGR system. The EGR valve and DPFE are usually close together above the exhaust manifold/downpipe. you need service instructions to test these items, suggest you go to a garage really...

SOURCE: error code 1159 told by the dealer it needs a part that cost over $500

The 3.0L and 3.5L engines in the XG300, XG350 and Santa Fe incorporate a Variable Induction System (VIS). The VIS is a secondary set of throttle plates in the upper intake plenum used to increase low end torque while maintaining high rpm performance. The Powertrain Control Module (PCM) uses a Variable Intake Motor (VIM) to control the opening and closing of the additional throttle plates called the Intake Control Valve (ICV).
At low rpm the (ICV) is closed and, as rpm increases, it is opened a specified amount for optimum airflow.
A VIS system condition is not likely to affect drivability, however, a diagnostic trouble code (DTC) may set. The DTC for the VIS system is P1159 (Variable Intake Target Position). The PCM controls the desired valve position and when the feedback of the
valve position does not correlate with the requested position this code is set. This DTC will not turn the check engine lamp on, however the code will remain in memory.
NOTE: P1159 has been changed to P2015 for the 2005MY.
Please refer to DTC P2015 in the 2005 Shop Manual for further diagnostic information on P1159. (XG350: page FL-555) (Santa Fe: page FL-633)
DTC DETECTING CONDITION:
ITEM DETECTING CONDITION POSSIBLE CAUSE
DTC Strategy Target position monitoring • Poor connection
• Open or short to battery
in harness
• VIS Motor or VIS Motor
Rotation Sensor
• PCM
Enable Condition Engine speed > 3750 rpm
Threshold Value Unable to obtain target value
Diagnosis Time Unable to obtain target position 4 times
MIL On Condition N/A

The VIM is not available as a separate unit from the upper plenum if replacement is needed, therefore the entire plenum assembly must be replaced.
NOTE: With the intake plenum removed, inspect the gear on the VIM to see if it has stripped. Carefully inspect the throttle plate retaining screws that attach the plates to the VIS shaft. If any of the screws are missing (2 screws per throttle plate) inspect for engine damage.
Once the intake replacement is completed (see appropriate Shop Manual for the vehicle you are working on) the Electronic Throttle Position System (ETS) should be re-initialized by turing the ignition key On and Off within 1 second. Then, wait 30 seconds before starting the vehicle. Refer to TSB 05-36-002 for the complete ETS
initialization procedure.

SOURCE: fault codes P0722 and P0717

You just need to replace the sensors. If you are mechanically inclined, you can do it yourself. If you don't feel comfortable working on an expensive transmission, take it to the dealer.

toneman2121

• 775 Answers
• Posted on Apr 21, 2010

SOURCE: check engine light on-code says egr valve is bad

the egr system consists of control circuits as well as the egr valve itself. troubleshooting will have to be performed in order to pinpoint the fault. the valve may just need cleaning. there may be damage in the long run since the egr system introduces exhaust gas to the air intake to reduce combustion temperatures.

http://www.aa1car.com/library/egr.htm

SOURCE: How much will it cost to fix code P0744 for a 2005

The possible causes of the error code you are facing are

• Torque converter clutch solenoid valve is faulty
• Hydraulic control circuit failure
• Valve body problems
• Or any problem with the clutches.