I have an 01 v6 with a 5 speed and recently the Service Engine Soon light came on. I have had the codes cleared twice both times they read the same codes. I know maintenance stuff and simple repair stuff but this is beyond me.

PO131 Oxygen Sensor Low Voltage Bank 1 Sensor 2
PO137 Oxygen Sensor Bank 1 Sensor 2
PO151 Oxygen Sensor Low Voltage Bank 2 Sensor 1

One tech said It could be a vacuum leak and I just did an intake resonator delete but everything is tight there and there are no leaks. The light came on the first time before I did anything so I don't think its something there. Does anyone have any idea whats going on? Input would be greatly appreciated.

 

Have you already replaced the O2 Sensors? How many miles on the car? Did you recently added an oiled air filter by chance? Have you cleaned your MAF wire recently with cleaner spray?

 

Sensors have not been replaced yet. The techs say its probably a false but it doesn't seem like it to me.

105000 give or take

No the filter is not new or oiled

No I have not cleaned the wire. I honestly didn't know it could be.

The resonator was removed and a pipe was fitted in its place. I didn't think that would have anything to do with it.

 

THis is a sign of bad o2 sensors. Whoever your "tech" friends are need to pay better attention to what the computer is telling you. Personally I would replace all 3 if I were you but at least replace the ones that are being called out. Bank 1 is the driver's side and bank 2 is the pass side. Sensor #2 is the one after the Cat and sensor #1 is the one on the manifold.

Massey

 

Yea, if you replace one, does the corresponding code go away? There's your test...

 

Some possibilities for consideration:


The heated oxygen sensor wiring-The sensor pigtail may be routed incorrectly and contacting the exhaust system.
Poor PCM to engine block grounds-Refer to Ground Distribution Schematics.
The fuel pressure-The system will go lean if pressure is too low. The PCM can compensate for some decrease. If fuel pressure is too low, a DTC P0131 may be set.
The fuel injectors-
Vacuum leaks-Check for the following conditions:
Disconnected or damaged vacuum hoses-
An incorrectly installed or malfunctioning crankcase ventilation valve.
Vacuum leaks at the throttle body, the Exhaust Gas Recirculation (EGR) valve, and the intake manifold mounting surfaces.
Exhaust leaks-An exhaust leak may cause the outside air to be pulled into the exhaust gas stream past the HO2S, causing the system to appear lean. Check for exhaust leaks that may cause a false lean condition to be indicated.
The Mass Air Flow (MAF) sensor-Disconnect the MAF sensor and see if the lean condition is corrected. If so, replace the MAF sensor.
Fuel contamination-Water, even in small amounts, can be delivered to the fuel injectors. The water can cause a lean exhaust to be indicated.
If none of the above conditions are present, replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) 1 Replacement

 

^ Woa, don't replace an expensive MAF sensor before first cleaning the MAF wire with MAF cleaner spray.

 

Ill swap out the o2 sensors and go from there, will keep you posted. Thanks for the input I appreciate it.

 

wanted to update for drivers with similar problem. cleaned the MAF with CRC MAF cleaner a few weeks ago. Light has yet to come back on again. problem solved. Thanks everyone who participated for the advise. It made my life a lot easier.