I have a 2004 Saturn Vue AWD V6. I can't clear OBD monitors...Oxygen and Cat. Did drive cycle etc? how to clear

The diagnostic trouble code (DTC) P0420 "Catalyst System Efficiency Below Threshold" is one possible outcome following the Catalytic Converter Monitor (test). This monitor is one of the last tests to be performed by the powertrain control module (PCM) because other failures in the system could compromise this test's result. Catalyst efficiency is tested by observing the oxygen sensor signals both before and after the catalyst. Before the catalyst, the signal should appear as a sine wave as it switches back and forth between rich (0.9 volts) and lean (0.1 volts). After the catalyst, the signal should be flat-lined on the rich side (about 0.7 volts). This is because a healthy catalyst will store oxygen and therefore remove the "lean" portion of the signal/waveform. If the signal after the catalyst still appears as a sine wave, the PCM concludes that the catalyst can no longer store oxygen and should therefore be replaced. In your specific scenario where a downstream (post-cat) O2 sensor was just replaced, I would theorize that this sensor had failed and was flat-lined. Then when it was replaced two things happened: 1.) the oxygen sensor began to work properly which allowed the oxygen sensor monitor (test) to complete, and 2.) the catalyst monitor then ran and used the new (accurate) sensor data to determine that the catalyst efficiency was below threshold. You can read more here: https://www.yourmechanic.com/article/p0420-obd-ii-trouble-code-catalyst-system-efficiency-below-threshold-bank-1-by-jamahl-walker

The Saturn Vue came in the FWD and AWD models. As built, for the AWD to work you need the driveshaft. If you remove the rear drive shaft and fix it so there would be no leakage, you could easily drive the Vue as a FWD vehicle.

2 x oxygen sensors --one after each cat converter
there are also 2 x heated oxygen sensors ( different operation and reporting system) that are before the cat converters or in the exhaust manifolds run the fault codes to find the faulty sensor and it probably isn't either o2 or ho2 sensors

Fig. Heated Oxygen (HO2S) location (bank 1, sensors 1 & 2) - 3.5L engine




Fig. Heated Oxygen (HO2S) location (bank 2, sensors 1 & 2) - 3.5L engine


Hope helps.

how do I loosen tension for serpentine belt

I have a 2002 saturn vue. Same thing..sounded like a jet engine ...loud humming as I accelerated . It got increasingly worse. It turned out to be the front wheel bearings. Replace them, now the noise is half as loud...have to do the rears also! 93,000 miles on it. Also, don't forget to replace the timing belt. It it goes too long and breaks, it will trash the engine...

Have you checked your wheel bearings? When these go out you can get a harsh grinding noise. This sounds like that is what it might be. Does it happen when you are going fast/slow turning/going straight? I know you said it's inconsistent but the more info the better. However, if I had to bet, based on what you have already said, it's your wheel bearings. Let me know if you have further questions. Thanks for using FixYa!

How do i check the transmission fluid in 04 awd v6 auto

Buy it new from many places Search Saturn Parts call local Dealer .
Happy Easter

No is not hard all you need to do is remove the tire and it haves four bolt on the back. one is kind of hard to take out do to not much space to work with.