Mine is (apparently) a genuine Lexus part... Less than half a genuine Jag part but exactly the same... I would not touch a copy or clone part!!!

 

Part-swapping is usually way more costly than diagnosis starting with the cheap & easy stuff.

 

Sorry , I have done a smoke test, to see if any vacum are present , than changes the maf sensor, than oxygen sensors, than breather valve, than EML light gone, but after a tank fillup light EML and restrict perform back on again?? Can it be the purge valve ??? Or ...????

 

I'm lost after so many posts - do you have both of the lean codes and what are the LTFT values (engine hot, parked, per bank) at 2500rpm and idle?

You've spent probably 10x, maybe 50x, cost of an OBD tool with live data.

 

Sorry Hombre but I have not seen any codes? So I am a bit lost too. You have done some troubleshooting but it has not worked because we are not sure where the problem lies.

Any chance of getting the codes read? Changing parts without knowing why is usually an expensive and inefficient way to fix it.
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I installed a new MAF sensor. While doing so I checked out the air box and discovered the damage in the photo to the lower air box assembly. I'm sure it was damaged by the local garage that changed the filter. They didn't say a word. Could this cause a lean condition? I suspect so but I'm asking for a second opinion. Here are my latest LT FTRM 1/2 readings at idle and 2500 revs.

1 at idle. 7.0 At 2500 revs. 4.6
2. At idle 5.4 At 2500 revs 5.4


MAF. .528 1.83

 

No it's still metered air but it is sucking in hot engine compartment air instead of thru the factory fresh air setup. Should not set a code but definitely fix it.

It's a shame when the repair guy does more damage than he fixes!
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Yes both banks lean, p0174 and p0171. Eml and restrict perform light comes on now only after a tank fillup, before changing the maf some parts it came on while driving the car often not like now, after a tank fillup. As the smoke test didn't show any vacuum leak, I am wondering that purge valve can be the problem? Fuel trims are a bit high aprox 10 %... Please advise!!!!!!?

 

Hi , codes are p0174 and p0171, now, AFTER, changing this parts lean codes for both banks, (Eml and restrict perform) only comes on after a tank fillup, so I am wondering if there can be something related to purge valve or ???
Fuel trims are a bit high, aprox 10%

 

So read and post the LTFTs. How can anyone give advice without proper data...

 

after MAF sensor replaced and air box temporarily repaired with metal 3m tape, no pending codes set after 25 mile run.

 

They're 2-trip codes...

 

Made second trip and no codes either set or pending.

 

Probably found and fixed (at least for now) the air leak. You'll know in time. Easiest way to check now is to do those LTFT checks.

 

How long do I wait before doing the long term Fuel Trim checks and do they represent a running average over a period of time much like the average fuel mileage?

BTW, the o-ring on the MAF sensor was old and had shrunk. Not sure it was a good seal. This problem came about immediately following a 80,000 mile check and oil change.

 

Any time now. A few drives and they'll have moved. If you really want to force it, disconnect the battery then after a few drives check for no codes but P1111 and check the LTFTs.

 

Just what actually is a good reading for LTFT?

 

Near 0. Why not just post them... This thread has gone on and on and on - you coulda read & posted by now.

 

I already did in post 66 but got no response.

 

No. See #64.