What are the probable causes of DTCs P1171 and P1175?

If you getting codes for the same thing on both sides of the engine you'll need to look at the parts before the fuel and air enter the engine. You need to look at the air intake system as well as the fuel parts. I'm assuming the air filter is new and clean? Sometimes the fix is that easy.
Have you checked and cleaned the MAF sensor, (Mass Air Flow Sensor). This reads air flow levels into the engine and uses it to adjust fuel levels going to the engine.
*Note* When you clean the MAF sensor use the correct cleaning spray and DO NOT go poking around inside the main opening. The MAF assembly uses a very fine wire as part of the sensor and this is VERY easy to damage.

Idle air control valve or passages clogged partly . Your best bet , take it to a qualified repair shop.

Clean out you idle air bypass valve with carb cleaner. P0031 air/fuel sensor 1 heater (B1)bank 1, p0603 engine control back up circuit,p1148 closed loop B1. Broken heater in upper O2 sensor is one if not all of your problems. Replace all of your O2 sensors & reset engine light.

code po172 is your bank 1 o2 sensor and code po121 is your throttle posit sensor that controls your RPMs .code po102 is your maf -mass air flow sensor. and code 01172 is a throw in code from the others cause problem. you need a o2 sensor and mass air flow sensor and throttle position senor

Hi there:

P0102 - Mass Air Flow (MAF) Circuit Low InputBasically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. A more technical description would be that the MAF circuit had lower than expected voltage (air flow). Other MAF sensor circuit DTC trouble codes are P0100, P0101, P0103, and P0104.


You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

A code P0102 may mean that one or more of the following has happened:The MAF may be disconnected, or a wiring connection may be badThe MAF may be dirty or otherwise contaminated (Note: if you use a reusable oiled air filter, be careful not to apply too much oil or that can contaminate the MAF).The MAF sensor may be faultyThe vehicle computer may be faulty (very rare)

Possible Solutions:The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.Inspect for any air leaks near the MAF sensor.Take the MAF out and clean it using a spray cleaner such as brake cleaner or electrical contact cleaner. Be gentle with the sensor.Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)Replace the MAF sensor.

P0135 - Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)This code refers to the front oxygen sensor on Bank 1. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0135.


A code P0135 may mean that one or more of the following has happened:O2 Heater element resistance is highInternal short or open in the heater elementO2 heater circuit wiring high resistanceopen or short to ground in the wiring harness

Possible SolutionsRepair short or open or high resistance in wiring harness or harness connectorsReplace oxygen sensor (cannot repair open or short that occurs internally to sensor)


P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)This code means that the heated circuit in the oxygen sensor on bank 1 decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0141. See also: P0135 (Bank 1, Sensor 1).


A code P0141 may mean that one or more of the following has happened:
open or short to ground in the wiring harnessO2 heater circuit wiring high resistanceO2 heater element resistance is highInternal short or open in the heater element
Note: Typically a failed catalytic converter does not cause this code. You're more likely to see a P0420 code for a failed converter.
Possible SolutionsReplace oxygen sensor (cannot repair open or short that occurs internally to sensor)Repair short or open or high resistance in wiring harness or harness connectors


P0443 - Evaporative Emission Control System Purge Control Valve CircuitThe Evaporative Emissions System (EVAP) allows fumes from the gas tank to enter the engine to be burned, rather than vented into the atmosphere as an emission. The purge valve solenoid is supplied switched battery voltage. The ECM controls the valve by operating the ground circuit, opening the purge valve at specific times allowing these gasses to enter the engine. The ECM monitors the ground circuit as well, watching for faults. When the purge solenoid isn't activated, the ECM should see a high voltage on the ground circuit. When the solenoid is activated, the ECM should see the ground voltage pulled low, close to zero. If the ECM doesn't see these expected voltages, or senses an open in the circuit, this code is set.


P0443 trouble code symptoms could be just an malfunction indicator lamp (MIL) illumination. There may be no drivability problems at all. But, it's also possible to have a lean condition or a rough running engine if the purge valve is stuck open. Usually though, these symptoms are accompanied by other EVAP codes. Another symptom may be excessive pressure in the gas tank in the form of a "whooshing" sound when the cap is removed, indicating a purge valve that isn't working at all or stuck closed.

To cause a P0443, there has to be a problem with the purge control CIRCUIT, not necessarily the valve. Usually they are a unit housing the valve and the solenoid as an assembly. Or it could be comprised of a separate solenoid with vacuum lines to a purge valve. That said, it could be any of the following:
Bad purge solenoid (internal short or open)Wiring harness chafing or rubbing another component causing short or open on control circuitConnector worn, broken or shorted due to water intrusionDriver circuit inside powertrain control module (PCM) is badPossible Solutions
1. Using a scan tool, command the purge solenoid to activate. Listen or feel for a clicking coming from the purge solenoid. It should click once, or on some models it may click repeatedly.
2. If it doesn't click with scan tool activation, unplug the connector and examing the solenoid and connector for damage, water, etc. Then check for battery voltage on the feed wire with the key on. If you have battery voltage, then ground the control side manually using a jumper wire and see if the valve clicks. If it does, then you know the solenoid is working properly but there is a problem with the control circuit. If it doesn't click when you manually ground it, replace the purge solenoid.
3. To check for a problem on the control circuit (if the solenoid tests okay and you have voltage to the solenoid) plug the solenoid back in and remove the control circuit (ground) wire from the ECM connector (If you're unsure how to do this, do not attempt). With the ground wire removed from the ECM, turn the key on and then manually ground the Purge valve control wire. The solenoid should click. If it does, then you know there is no problem with the control wire to the solenoid and there is a problem with the ECM purge solenoid driver circuit in the ECM. You'll need a new ECM. However if it doesn't click, then there must be an open in the wiring between the ECM and and the solenoid. You must find it and repair it.

Hope helps.

Most of the time a lean condition is a vacuum leak! The O2 sensors are doing exactly what they are supposed to be doing.

A car is like algebra nowadays- The MAF and other sensors tell the computer that the car has "X" air coming in. The Computer then adds "Y" amount of Fuel based on reading "X" Then the O2 sensors read what comes out the other end and it should be for example "Z".

When a vacuum leak occurs you end up intruducing more air than the sensors are saying is in there. So the "Z" value is different.
Then POP goes the engine light on.

I would look for a vacuum leak on a lean condition before I started changing Fuel filters.

2 airflow sensor out of operating range 3 coolant temp sensor out of operating range 4 oxy sensor indicates full rich 5 throttle potentiometer/airflow sensor... (low throttle pot signal with high airflow sensor signal) 6 throttle pot/airflow sensor...... (high throttle pot signal with low airflow sensor signal) 7 throttle pot...idle fuel adjustment failure(idle speed??) 8 intake air temp sensor...open or shorted circuit to sensor 11 Throttle pot at idle: Throttle pot idle trim out of normal range 12 Airflow meter: MAF signal out of range 14 Coolant thermistor: Resistance out of range or static during engine warm up 16 Air thermistor: Resistance out of range 17 Throttle pot: Out of range 18 Throttle pot/Airflow: Low throttle pot signal at high airflow 19 Throttle pot/Airflow: High throttle pot signal at low airflow 22 Fuel pump drive: ECU output to fuel pump relay 23 Fuel supply: Engine running too rich 24 Ignition Drive: ECU output to ignition Amp 26 Air leak: Engine running too lean 29 ECU self check 33 Injector Drive: ECU output to injectors 34 Injector: Looks for Injector dribble 37 EGR Drive: ECU output to EGR switching valve 39 EGR check sensor: EGR not working (normally pipe blocked) 44 Lambda (O2) sensor: Poor mixture control rich or weak (or misfire) 46 Idle speed Control valve: ECU output to Coil AB 47 Idle speed Control valve: ECU output to Coil CD 48 Idle Speed Control Valve: Stepper motor grossly out of position 66 Air pump: ECU output to air pump relay 68 Road speed sensor: Seen speed < 5km/h at high engine airflow 69 Drive/Neutral switch: Seen cranking in "D" or high airflow in "N" 89 Purge Valve drive: ECU output to purge valve
this is all I could find

I have a van that had a similar problem. Not sure if the rodeo has O rings. That was my problem.

P0446 - Vent Control of the Evap System. This Evaporative Emissions System is very complicated. These particular DTCs (Diagnostic Trouble Codes) can be caused by MORE than they tell you. Three MAJOR components in the system can cause this P0446. 1. Charcoal Canister, 2. Charcoal Canister Filter, 3. Canister Close Valve, 4. Fuel Tank Pressure Sensor, 5. Purge Control Solenoid Valve, 6, Wiring and/or connector/connections between them and the ECU. If you wish to trust the computer's diagnostics, then replace the canister close valve (after you have inspected the Evap Charcoal Canister's air filter and find no problems with restrictions of air flow). If the problem comes back, check the Purge Control Solenoid Valve and the operation of the Fuel Tank Pressure sensor - either one of those components, if malfunctioning, can cause a P0446.

Really the sky is the limit here. See when you first start vehicle the computer is in open loop which means it is not monitoring the O2 sensors and fuel control is set to a calibrated setting. After the Heaters heat up the O2 sensors it then goes into closed loop and starts monitoring the O2 sensors to control air/fuel. So anything in the fuel and air mix could be causing your problem like false air volume reporting from the MAF sensor,a vacuum leak,unmeasured air getting into the engine behind the MAF sensor from a leaking hose,,a faulty pcv system,lazy O2 sensors, etc.
I would first recommend cleaning the MAF sensor and resetting the keep alive memory.Get a T20 torx bit and remove the MAF and get some electrical cleaner and spray the MAF bulbs clean then let it air dry or blow it dry with light shop air. Then disconnect battery for about 30 minutes to reset the strategies and see if this cures your problem. It will take probably 50 miles of driving for the strategies to reset.