subal

I have a K & N air filter on my rx300.
Where is the oxygen & MAF sensors located and how do I clean them?

Thanks,
Allan

Fern

Here is a great link to a previous post on the cleaning of the MAF sensor.

BTW, you don't need to clean the oxygen sensors.. Your K&N filter is not doing anything to the oxygen sensor.

Its the MAF sensor that you should be concerned with. Be very careful not to damage the hotwire in the MAF sensor when handling it. Let it completely dry before re-installing it.

https://www.clublexus.com/forums/sho...ght=MAF+sensor

Cheers,

Fern

Erwel

hi to al,

i have 99 rx 300 it has 70,000 miles in it. its starts to show the check engine light. I have a engine code reader and it shows code po 171 which is bank 1 fuel mixture lean. i have k&n filter in my engine. Is any of
you guys experience this problem?

thanks,

Fern

This lean condition sounds more like an oxygen sensor than the MAF sensor.

Can someone else can provide more input...?

Sounds like one of your oxygen sensors is sending a wrong signal to the ECU...

Erwel

I cleaned the maf sensor with carb cleaner and used a cotton buds to carefully clean the diode. right after 5 minutes of driving the check engine light went away. I think, the diode is giving the ecu a wrong signal. what it does is to measure the amount of air flow and dispense the right amount of fuel based on the amount air going into intake. if the diode is dirty or covered by oil from the k&n filter, it will sense a low air flow and it will not give enough fuel. if this happens the o2 sensor will detect a lean condition. This is what I think, correct me if Im wrong

Lexmexico

That is correct. One thing to add is that when this occurs, the car goes into an automatic mode regarding air flow and air temperature. However, when this problem first occurred with my car, I do not think this kicked in immediately. Part of the paint on the engine cover literally melted.