Code PO 172 and PO 175 System Lean Bank 2 2000 Mustang V6 Shop says Maniforld right side is broken and that may Cat's plugged possibe 02 Sensor Relace plugs 111,000 mi on care Dies at stop signs, idle high and low jerks Uses lot's of fuel. Any ideas Would the manifold effect the fuel system Would replacing the 02 sensor take care of the problem

that is not the OEM makers statement on P0401.
truth is this. V6 engine? 3.3L and 3.5L???????
o2 sensor circuit no activity detected bank 1 sensor 2)
means the right rear 02 sensor reads dead.

right bank down stream 02 is dead.

and has zero to to with rich or lean, it is the rear sensor 2.
the rear sensors are only to this bank1 CAT for good quality.
not told at all , what engine is there. v6 sure,3.3 or 3.5L
nor how the engine runs and car drives. ?
or if this is ONLY a smog question and check engine lamp glows?
causes of 401 are
wires to right rear 02 cut burned or damaged , loose or fell off 02.
bad o2 B1,S2 rear of cat bad
bad CAT bank1,
exhaust cracks in CAT sucking air and making any 02 sensor to read dead, near it.
this post ASSUMES , no other DTC errors stored or live running,
assumes scanned LTFT PID reads correctly and no B1S1 02 errors.(front sensor)
bank 1 or B1 is right front engine bank. (drivers view)
facing engine is left bank. (workers viewed)
ASSSMEs car is driven plenty not just parked in an old barn.
A DRIVEN CAR !

SMog tests fail too for monitor cat bank1 dead.
or incomplete status on bank1 cat.

It doesn't have to be the sensor ! http://www.autocodes.com/p0174_hummer.html

Yes, too lean is the problem. Just means "not enough gas" is flowing. Could be as littlie as a plugged up gas filter or worst scenario, a bad fuel pump. Either way, it isn't getting enough fuel into the engine. When it WAS running, and you pushed the throttle all the way open, it was then getting way too much air for what little fuel was going in. That's why it did what you said.

each side of the engine is called a bank bank one has cylinder number one and bank two has cylinder number two sensor one is before the cat converter and sensor two is after the cat

P0154 - 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
The oxygen sensors are critical to the engine running properly. It basically informs the PCM (Powertrain Control Module) of oxygen content of the exhaust. The PCM then uses this information to regulate fuel into the engine and maintain proper air:fuel ratio. It is a four wire sensor, with the PCM providing a reference/signal voltage of about half a volt (0.5v) to the sensor. It usually provides a ground also. The other two wires are dedicated to the oxygen sensor heater element. This heater allows the sensor to warm up faster, which allows the engine to enter closed loop faster, reducing startup emissions. The heater element is supplied a 12v feed from the power distribution center (usually) and a ground.

The oxygen content of the exhaust affects the O2 sensor resistance. This resistance produces a counter voltage on the reference/signal wire that the PCM will use to analyze oxygen in the exhaust. Lean exhaust produces low voltage, while rich exhaust produces high voltage. The oxygen sensor is capable of varying between 0.9v (rich) and 0.1v (lean). Once the engine reaches closed loop, the O2 sensor should begin switching rapidly between rich and lean voltages 2-3 times per second. If for some reason the O2 sensor doesn't switch properly or "sticks", P0154 may set. This code indicates the O2 sensor isn't operating.


P0174 - System Too Lean (Bank 2)
Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.

You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.


If need additional details, just contact us. Hope this helps.

Bank 1 is at the back of the engine compartment next to the firewall. You'll need to know if you need to change (bank 1 sensor 1), or (bank1 sensor2). Sensor 1 is located in the exhaust system between the rear cylinder head and the catalytic converter. Sensor 2 is after the cat in the exhaust system after the cat.

P1131 - Insufficent Switching 02 Bank 1 Sensor - 1 Sensor / Lean.

Sensor 1 on bank 1 is the passenger's side upstream 02 sensor.

Start by cleaning the MAS and Filter and see if this helps. If not, you will probably need to replace the O2 sensor.

It COULD also be a bad No.2 injector I believe

PO 134 = 02 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR1)
PO 153 =02 SENSOR CIRCUIT SLOW RESPONSE (BANK 2 SENSOR 1)
PO 154 =02 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 2 SENSOR 1)
PO 155= 02 SENSOR HEATER CIRCUIT MALFUNCTION (BANK 2 SENSOR 1)
PO 171= SYSTEM TOO LEAN (BANK 1)
PO 174= SYSTEM TOO LEAN (BANK 2)
I WOULD SAY YOU HAVE FAULTY OXYGEN SENSORS CAUSING THE ENGINE TO RUN TOO LEAN REPLACE THEM AND YOU SHOULD BE BACK IN BUISNESS

P0171------ system too lean bank#1
Po174------ system too lean bank#2
For these 2 codes, try cleaning the maf sensor (mass air flow), that is mounted in the big black hose that goes from the air filter housing to the throttle plate, if it is dirty, that will cause those 02 sensors to send a signal to the computor to lean the air fuel mixture. If cleaning it doesn't work, the sensors will probably need changing.
P0300---- Random/multiple cylinder misfire
P0316---- Cylinder misfire at start up---- first 100 revolutions.
On those 2 codes, you have to do some testing to find out why there is a misfire.
Possible causes:
dirty/malfunctioning injectors
weak coil pack
fowling spark plugs/wires
Low fuel pressure

check o2 sensor rear of cat/ converter for short ,damaged wires or faulty sensor--if exhaust leak repair leak or cat/converter plugging up or restricted