hi i got my enine light on. i whent to sucks nad thay tasted and say. that i have problems with codes
P0171
P1133
P1155
for P0171 it says system too lean. they told me that not enought air for ingectors. so i chek my air filter, and there was rat nest so i cleaned. but the light stil on and they couldn't give me information for others codes
can enyone help me with this? thank you very much

 

P0171 is the most common error that will occur on the RX300. It actually is a lean error too much air for the amount of fuel. Ignore this error as it is an accompanying error that will usually pop up when you have a P1155 or a P1133.

P1155, A/F sensor Heater Circuit Malfunction, Bank 2 Sensor 1. This is the front A/F sensor that if you take a look in the engine bay, it will be this one clearly visible just in front of the engine block.

 

P1133 is related to just the opposite sensor behind the engine block, bank 1 sensor 1 (shown below)

With both of these errors cropping up along with a P0171, there are two possibilities:

1) 1 or both of your A/F sensors are done for. Only way to truly check this is to have a mechanic with a scanner that can read the signals coming out of the A/F seensor to see if 1 or both are dead. This does not require going to Lexus or Toyota. There are, but I have no experience with any one specifically, very expensive scanners and also slightly less expensive computer software with cables that can be hooked up to a laptop that can also check these and other signals.

2) If you are so fortunate (I hope), what may have occurred was purely that the Air/Fuel (A/F) was out of range for a moment and caused the the Light. The best thing to do (and I won't go into the EFI fuse situation as others other used to with regard to my recommendations) is to pull BOTH the negative and positive cables on the battery for about 15 minutes, reattach and then take a drive of at least 1 hour (50% city/50% highway). In the alternative given high gas prices, just drive as you normally would over the next few days. To see if a light occurs. If it does, then number 1 is the option.

Note: pulling the battery cables will reset your clock, radio stations and seat settings among other thins, but won't do anything more harmful than that.

 

please be prepared to spend around $400 on this repair. All RX300 owners have or will encounter this issue

 

what about if i will pull it out and clean that. is that gonna help?

 

It may for a while but it WILL Fail. Those are among common problems with the RX300. i quickly realized that and accepted it.

 

This is a view of the sensor on Bank 1, Sensor 1. If it were me at my mileage, I would (after checking the sensor readings via scanner) just replace them.

However, being adventurous best thing to use here is an electronic contact cleaner. Now, in the U.S. they sell this kind of stuff at Radio Shack. There is a company called CRC that makes one along with a very good MAF sensor cleaner. I have heard of using throttle body cleaner, but since I wouldn't touch a MAF sensor with a ten foot pole with throttle body cleaner, I have relied on of all things computer keyboard cleaner for that (found at WalMart).

 

i fanaly change all may oxygen sensor but eingen light still on and it says P0171 it says system too lean. what should i do? thank you

 

Has the P0171 error been staying on all the time or have you tried to reset it and it comes on shortly afterwards?

 

yes they reset mi and after 30min of driving it pup ups.

 

is it doing anything that you can notice besides the code? sputtering, misfiring, etc...

 

A few things you can try: 1. adding a fuel injector cleaner to alleviate any issue with the injectors and potential blockage of fuel delivery causing current lean condition, 2. Check all air hoses in the engine bay (I don't think this is it), 3. Clean the MAF sensor after the airbox, 4. An outside possibility if the coolant is old is an engine coolant temperature sensor, 5. Take a look at the picture on post 2 above and you'll see some welding having been done. I would examine that area and also the joint below the motor to see if there are any holes in the exhaust. I know from experience any kind of crack in the exhaust will pop a P0171 code.

 

Did you use the oem Denso A/F sensors?? or the Bosch stuff?