2003 jeep grand Cherokee with the 4.0 has a code

kia ora Mark , greetings , sorry bro these code things are beyond me ive been driving around with a p0161. i believe its a bank2 down stream sensor for 2 years , maybe you can help me , 2002 grand cherokee 4.7 Ho , do you know what brand of sensor or part numbers i need , an idea of cost for same . i forgot to mention i am in New Zealand and auto parts are so much more expensive here , no idea at all , much help needed everyone thank you all , hope you get sorted Mark cheers mate

check the tps and iac on throttle body

I would check Cam Position Sensor as is directly related with ignition. Power loss is due to the ECU going on "limp mode" to prevent further damage.
I hope this helps!

YOU HAVE INTAKE VACUUM LEAK AT THROTTLE BODY OR PCM HAS FAILED.NOT CONTROLLING IDLE SPEED CONTROL CIRCUIT.

P0505 - Idle Air Control System Malfunction The PCM attempts to control engine speed during KOER self-test. The test fails when the desired rpm could not be reached or controlled during the self-test. IAC circuit open
VPWR to IAC solenoid open
IAC circuit shorted to PWR
Air inlet is plugged
Damaged IAC valve
Damaged PCM
The IAC solenoid resistance is from 6 to 13 ohms.

Check it.

have you checked the IAC, idle air control,or cleaned the throttle body and plate.

P0505 means the whole Idle Control system, not only the IAM. Check all related sensors (i.e. crankshaft sensor). Check with a voltmeter direct at the connector of the IAM if you get any signal. Remove the IAM from the TB, connect him, let someone switch your ignition key to ON. The IAM need to drive in/out for a short time to find the right position. Hold the IAM near a hard part, that they cant drive out completely! If IAM works fine, check the fuel pressure, check and clean your TB ( if not done yet). If that doesn't work, come back again please

Drive it for a day or so & clear codes again. That new code may have been set by part replaced. See what happens.

That error code is idle control system malfunction.  You need to replace your idle air controller (IAC). IAC basically opens and closes the throttle at idle so it stays at constants RPM.  Hope this helps.  Thanks for an honest rating and for using FixYa.

po743 is torque converter curcuit electrical. i would check and see if the torque converter clutch switch is ok!!