P0171

[Germ2112]

Hello all,

99 RX300

Well about three weeks ago I took a trip of about 300 miles and on the trip I got a CEL that came on while driving home. Stopped and tightened the gas cap to be certain and the light stayed on. Disconnected Battery but it came back on. Had Autozone run the scan and got P0171.

The guy at Autozone suggested he thought it was the O2 sensors. I went to a local Mechanic who said the MAF meter. The light was going on and off every so often (not flashing). I cleaned the MAF and the light went off for a bit but came back on. I replaced the MAF myself as well as Air filter and put in fuel injector cleaner. Once this was done the light did go off on its own after a bit but after 50 miles it reappeared.

Do I need to reset the engine light by disconnecting the battery or is there anything else you can suggest since the light comes on a goes off every so often.

How can I check the gas cap to be sure it is not de-presurizing?

when do I need to get it into the shop after exhausting all simple solutions?

Thanks all!!

[tong]

I have the same code P0171 about one year ago on my 2000 RX300. I cleared the Mass Air Flow Meter several times and put bottles of injector cleaner into the gas tank but the code still comes out. I checked the vacuum for leak but found no. The car runs good just the mileage is down.

I decided to replace the meter and order the meter from Park Place Lexus Plano at Texas. After change the meter with the battery cable off, the code is gone and has not come back for 3 weeks and hundred miles. I think it fix the problem.

So, you can clear the meter first with Choke & Throttle body cleaner. If it's not work, replace the meter. The part # for this meter is 22204-07010 for about $120.00 and the replacement is very easy.

[lahermano]

I have the same issue, got cel and autozone told the same

I wanted to replace myself. How and where it is located and what tools are needed ?

appreciate any guidance in performing this task.

Thanks

[carguy07]

This shows how to clean one. Just pop a new one in if you want to replace.

http://www.lexusownersclub.co.uk/knowledge...id=152&c=11

[lahermano]

Thankyou very much.

Been very helpful. I am going to do it myself. Will get the CRC electronic cleaner and clean the MAF and reinstall.

Very easy to do.

Thanks again.

[R.Holmes]

Thankyou very much.

Been very helpful. I am going to do it myself. Will get the CRC electronic cleaner and clean the MAF and reinstall.

Very easy to do.

Thanks again.

If cleaning or replaceing the MAF,doesn't solve your problem, check for vacum leak in the vacum booster. That is where my problem was