Have read a number of threads about the CEL coming on in RX 300s...from what I can tell, this seems a fairly common occurence once the vehicles get 40K+ miles on them. Diagnostics run from lean system to O2 sensors to MAFs etc. Here's my question...if one is working through the various possibilities for what is wrong when the CEL comes on, is any harm done if it takes a while to determine the cause, i.e., does it do any damage to continue driving the car with the CEL light on? I'm getting a CEL with diagnostic of "lean system" (bank 1 and bank 2)...not real sure as yet what's causing it but have a 1000+ mile trip I'm planning to take...it this risky? Am driving a 2000 RX with 78,000 mi on it.

 

Well you might find yourself wasting a little more gas with a problem like that. Would be interesting to know and to assist what the actual Pxxx OBDII code is as having both banks throwing an error at the same time is a little rare (bank 2 being the front manifold and bank 1 being the back). In addition, when did you first notice this error and have you tried to eliminate the code?

 

LEXMEX-
checked the OBD code again today...my error...was a 0171 from Bank 1. Also have a Pending 0171.

edo250

 

Here is the P0171 list again,

1. Air intake (usually a hose, i.e., the hose on the back of the airbox).
2. Fuel line pressure- fuel pump, fuel filter, fuel line injectors. 3. Injector blockage
4. A/F sensors
5. MAF sensor
6. Engine coolant temperature sensor

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The most common one has always been the MAF sensor and the little red diode and the wires inside the sensor getting dirty. Even if you reset the code, if you don't clean it, it will come back.

The A/F sensor is not an impossible culprit here, but usually other OBDII codes pop up.

I'd take a close look at the MAF.

I have driven with P0171 errors plenty of times, sometimes just as soon as I leave my home and go up to the track, reset the light at the trac and fly down the track several times, and no other issues.

 

thanks for the response...I cleaned the MAF a couple of hours ago...how do I clear the codes?

ed0250

 

Pull the negative battery cable or the EFI fuse in the fusebox. See the sticky thread at the top of the RX300 forum, https://www.clublexus.com/forums/sho...d.php?t=295546