Sensor code P0404 -- emissions system

P0171 is an oxygen sensor code meaning the engine is running too lean You did not specify what year make model nor engine size. You may have a vacuum leak or a MAF sensor problem causing this issue. It can also be a defective oxygen sensor. The engine data should be scanned to isolate the problem by a qualified shop

EOBD II Error Code: 25
Description:
System too Lean, Bank 1
Possible Causes:
- Intake/exhaust leak.
- Secondary air injection (AIR) system.
- Manifold absolute pressure (MAP) sensor.
- Mass air flow (MAF) sensor.
- Fuel pressure/pump.
- Injector(s).
- Evaporation emission (EVAP) canister purge valve.
- Heated oxygen sensor (HO2S).
- Contaminated fuel.

EOBD II Error Code: 26
Fault Location:
System too Rich, Bank 1
Description:
- Evaporation emission (EVAP) canister purge valve .
- Fuel pressure.
- Injector(s).
- Heated oxygen sensor (HO2S).
- Contaminated fuel.
Hope that works.

P1684
It is not a fault code per say, it only indicates the battery has been disconnected or went dead in the last 50 drive cycles I believe.
P1683
This code refers to the cruise control speed servo power circuit is open or shorted. The power comes through a normally-on contact in the brake light switch. Use a test light or voltmeter to measure the voltage on the yellow wire / red stripe on the switch. If it's there, measure on the dark blue wire / red stripe. If it's missing there, the switch is defective. The voltage should go to 0 volts there when the pedal is pressed.
The rest of the fault codes are as follows.

P0135 - O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
Possible causes- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Engine Control Module (ECM) Help with thisTech notes The code means that there is a problem with the heater element circuit of the heated oxygen sensor. The control module monitors how long it take the sensor to warm up and start sending an adequate signal. The code is triggered when the sensor is taking too long to warm up. Water getting inside the heated oxygen sensor connector can caused the heated oxygen sensor fuse to blow. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. If the sensor and connector are OK, replacing the O2 Sensor 1 usually takes care of the problem.

P0442 CHRYSLER - Evaporative Emission Control Small Leak Detected.
Possible causes- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
P0455 CHRYSLER - EVAP System Large Leak.Possible causes- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking Tech notes The P0455 it's a very common code, because the code is set if the gas cap is loose or missing. Start by tighten the gas cap and clearing the code. In most cases the code can be clear by disconnecting the car battery for about 30 minutes.

P0442 FORD - Evaporative Emission System Leak Detected Small Leak

Possible causes- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
P0136 - O2 Sensor Circuit Malfunction Bank 1 Sensor 2
Possible causes- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Faulty Rear Heated Oxygen Sensor Bank 1
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks

P0141 FORD - O2 Heater Circuit Bank 1 Sensor 2

Possible causes- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit fuse
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit poor electrical connection
- Faulty Engine Control Module (ECM)

Converter is not working as efficiently in Bank 1 and Bank 2 (two codes)...

P0421 - Warm Up Catalyst Efficiency Below Threshold (Bank 1)
Basically this means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

Symptoms: You will likely not notice any drivability problems, although there may be symptoms. The code may be more likely to occur after the engine has had numerous cold starts in the past 1-2 days.

Causes: A code P0421 may mean that one or more of the following has happened:
The catalytic converter is no longer functioning properly
An oxygen sensor is not reading (functioning) properly
A sparkplug is fouled up

Possible Solutions:
Measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

P0431 - Warm Up Catalyst Efficiency Below Threshold (Bank 2)
Basically this means that the oxygen sensor downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

Symptoms: You will likely not notice any drivability problems, although there may be symptoms such as a rough/hard idle when cold.

Causes: A code P0431 may mean that one or more of the following has happened:
The catalytic converter is no longer functioning properly
An oxygen sensor is not reading (functioning) properly
There is an exhaust leak

Possible Solutions:
Inspect for exhaust leaks. Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.


Hope this helps.

Hello,
P1131 = Lack of HO2S11 switch - sensor indicates lean, ( upstream heated oxygen sensor )
This oxygen sensor is located before the catalytic converter, ( refered to as UPSTREAM )

P1151 = Lack of HO2S21 switch - sensor indicates lean, ( could be up, or downstream heated oxygen sensor ) " Downstream ", meaning after the catalytic converter.

PO174 = System too lean, ( bank 2 ) The fuel/air mix ratio is bad.

These DCT codes are generally caused by a problem with the emissions system. The following items are a few of the most common items to trigger those codes.

1. Dirty air filter. ( very common )
2. Faulty idle air control valve. ( common )
3. MAF, ( mass air flow ), sensor. ( very common )

All 3 of the above can prevent the onboard computer from determining the proper fuel/air mix ratio.
The oxygen sensors measure to insure the fuel/air mix produces maximum power with minimal emissions.

I hope this helps you.
Feel free to contact me in the comment section if you have a question.

its is bad replace your oxygen sensor.

16716/P0332 - Knock Sensor 2 (G66): Signal Too Low Possible Symptoms

• Irregular rpm
• Drivability problems
• Loss of power
• Engine damage

Possible Causes

• Circuit G66 short to Ground
• Circuit G66 open
• G66 improperly torqued
• G66 damaged
• Control Module damaged

16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold Possible Causes

• Leakage in Intake and/or Exhaust System
• Catalyst faulty
• Oxygen Sensor(s) faulty
• Oxygen Sensor(s) Control faulty

Possible Solutions

• Check Intake and Exhaust System for Leaks
• Check Catalyst
• Check Oxygen Sensor(s)
• Check Oxygen Sensor(s) Control
  • Perform Oxygen Sensor(s) Aging Check

Sounds like you have low fuel supply or a leak in intake system causing lean codes, check fuek pressure and volume first. Cat converter effeciancy could be caused by the lean codes, purge system sounds like solenoid failure, check for high resistance accross purge vent solenoid.

Start by removing the EGR and clean it, or replace it. (They usually get gummed up with carbon) This would be the best place to start.