My lexus rx 300, '99 model is experiencing this prob. I did scanning and I got the following report:
P0171- System too lean Bank 1
P0100- Mass or volume air flow A circuit
C0301- Please refer to vehicle service maual
P0141- O2 sensor heater cirucit Bank 1 sensor 2
P0441- Evaporative emission system incorrect purge flow
P0446- Evaporative emission system vent control circuit.

After clearing, only P0171 and P0141 were showing.
Please I need your suggestions and ideas on fixing the problem.

My MAF sensor reads 0.01 when the live performance was checked. I tried two different tokunbo MAF sensors but the smoke was still coming out. So, I am guessing it's either not a problem of the MAF sensor, or the tokunbo MAF sensors are not okay themselves.

Check ur fuse box for any broken fuse(s) and replace.

lobito007:
My lexus rx 300, '99 model is experiencing this prob. I did scanning and I got the following report:
P0171- System too lean Bank 1
P0100- Mass or volume air flow A circuit
C0301- Please refer to vehicle service maual
P0141- O2 sensor heater cirucit Bank 1 sensor 2
P0441- Evaporative emission system incorrect purge flow
P0446- Evaporative emission system vent control circuit.

After clearing, only P0171 and P0141 were showing.
Please I need your suggestions and ideas on fixing the problem.

My MAF sensor reads 0.01 when the live performance was checked. I tried two different tokunbo MAF sensors but the smoke was still coming out. So, I am guessing it's either not a problem of the MAF sensor, or the tokunbo MAF sensors are not okay themselves.

Typical of lexus just remove and replace the faulty o2 sensor and black smoke will disappear.
The faulty O2 sensor is actually sending wrong signal ''system too Lean" to the ecu and the ecu is now overreacting by dumping fuel into the system and that is why u have the black smoke.

honmusa:

Typical of lexus just remove and replace the faulty o2 sensor and black smoke will disappear.
The faulty O2 sensor is actually sending wrong signal ''system too Lean" to the ecu and the ecu is now overreacting by dumping fuel into the system and that is why u have the black smoke.

Ok. I guess you are referring to the Bank 1 sensor 2 that came out in the scan. This sensor was not attached when I bought the car, because the catalyst to which the sensor was attached was removed and replaced with a pot which has no opening for the sensor, and it was not smoking until recently. So are you saying I should change this same sensor, or another?

lobito007:

Ok. I guess you are referring to the Bank 1 sensor 2 that came out in the scan. This sensor was not attached when I bought the car, because the catalyst to which the sensor was attached was removed and replaced with a pot which has no opening for the sensor, and it was not smoking until recently. So are you saying I should change this same sensor, or another?

u can detach all the O2 sensor in turn to get faulty one that is causing the issue or u call my number on my signature ,I can lend u some remote support.

honmusa:

u can detach all the O2 sensor in turn to get faulty one that is causing the issue or u call my number on my signature ,I can lend u some remote support.

Ok. What's your location, please?

lobito007:
My lexus rx 300, '99 model is experiencing this prob. I did scanning and I got the following report:
P0171- System too lean Bank 1
P0100- Mass or volume air flow A circuit
C0301- Please refer to vehicle service maual
P0141- O2 sensor heater cirucit Bank 1 sensor 2
P0441- Evaporative emission system incorrect purge flow
P0446- Evaporative emission system vent control circuit.

After clearing, only P0171 and P0141 were showing.
Please I need your suggestions and ideas on fixing the problem.

My MAF sensor reads 0.01 when the live performance was checked. I tried two different tokunbo MAF sensors but the smoke was still coming out. So, I am guessing it's either not a problem of the MAF sensor, or the tokunbo MAF sensors are not okay themselves.

Its good you took note of the codes then erase them. However, drive for a minimum of 50km and rescan for any codes.
That said, tackle the P0171, and the P0141
C0301 isn't a lexus DTC code. However, P0301 is a generic code which means cylinder 1 misfire detected.

P0171 means your intake system, your PCV, your EGR etc is dirty. Replace the air filter, check air intake hoses for breakage or leaks, if any, replace the hose. Use clips to securely tie any expanded hose. clean throttle body, (dont use your hand to touch the butterfly valve) PCV and EGR, clean MAF if dirty. Replace intake manifold plenum, if all these isn't working (which I know would work 90% of times) do a LTFT and STFT test before you replace A/F sensor Bank 1 Sensor 1,
as for the P0141, replace the O2 sensor Bank 1 Sensor2 after the LTFT and STFT diagnosis.


To properly handle this delicate issue, call Gazzuzz, 08023251039 if you're in Lagos, or lomomike 07034581213 if you're in Abuja.
You can read thru this threads for more clearity
https://www.nairaland.com/2649338/abuja-environs-remotely-follow-car
You should go thru the whole of this thread for your benefit https://www.nairaland.com/1487612/club-lexus

lobito007:
My lexus rx 300, '99 model is experiencing this prob. I did scanning and I got the following report:
P0171- System too lean Bank 1
P0100- Mass or volume air flow A circuit
C0301- Please refer to vehicle service maual
P0141- O2 sensor heater cirucit Bank 1 sensor 2
P0441- Evaporative emission system incorrect purge flow
P0446- Evaporative emission system vent control circuit.

After clearing, only P0171 and P0141 were showing.
Please I need your suggestions and ideas on fixing the problem.

My MAF sensor reads 0.01 when the live performance was checked. I tried two different tokunbo MAF sensors but the smoke was still coming out. So, I am guessing it's either not a problem of the MAF sensor, or the tokunbo MAF sensors are not okay themselves.

Can I ask you one question, do you have to top up your Oil?
next question are you using more than enough petrol ie more petrol consumption?

lobito007:

Ok. I guess you are referring to the Bank 1 sensor 2 that came out in the scan. This sensor was not attached when I bought the car, because the catalyst to which the sensor was attached was removed and replaced with a pot which has no opening for the sensor, and it was not smoking until recently. So are you saying I should change this same sensor, or another?

Im surprised at this event still

pay attention to the MAF sensor, during data stream you had 0.01!? the MAF shouuld give you about 0.4g/ms @KOEO, then about 3.5-7g/ms @ KOER, then about 10-20g/ms @ 2500RPM, did you take readings from the tokunbo sensors too?