kyote

Can someone help with information on CEL lights codes for 2000 RX300? Have codes - P0125, P1135, P0171, P1130.
I seen a previous post that the P1135, P0125 and P1130 probably has to do with the Air/Fuel sensor on the exaust manifold (probably the back one ?). Does anyone have an idea on the P0171. Runs great most of the time, occationally will have a problem with running sluggish and bad fuel economy, run injector cleaner and clears up, but now I'm getting codes.

Any help will be appreciated.

code58

Koyote- Do you have a code reader or scanner? I will give you the same advice I give everyone. In this day and age, either you need a rather thick wallet (no small bills, only large ones) or a code reader or scanner and some tools. 1st thing you ALWAYS do is cancel the CEL and then drive it and see what comes up 1st! Rarely will you have the same thing come up when you check it then. It does look like you may need a new A/F ratio sensor on the rear bank (B1S1). If the P1130 & the P1135 come up 1st. i would probably go ahead and change the rear sensor. the cheapest place you can get it is from Amazon.com. DON'T use an aftermarket sensor. They often give problems and then have you chasing your tail because you "know" it can't be the sensor because you put a new one in. But alas, you used "aftermarket" which many times doesn't "play well" with Toyota/Lexus (and a lot of others). The Denso OEM are sold on Amazon with a Denso # (cheapest price) but are the exact sensor without the Toyota #. Change that and then clear the CEL again and see what, if anything comes up.

Here is a good source for information on DTC's. It should take you to the "Lexus specific" page and then when you're done there you can click on the top of that page on "generic DTC's" (P0XXX) to find the P0125 & P0171. Whenever a line is "blue" you can click on that to take you to a diagnosis and repair for that code. If you need more info, come on back.

code58

Sorry Koyote, I copied the link and then forgot to post it. By the way, the Denso #'s for the sensors is 234-9009. They are both the same (R&L)

http://www.obd-codes.com/trouble_codes/lexus/