2007 Toyota Corolla Mass Air Flow Sensor/ System too Lean

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ewwjunior
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Joined: Thu Apr 11, 2013 4:15 pm

2007 Toyota Corolla Mass Air Flow Sensor/ System too Lean

Unread post by ewwjunior » Thu Apr 11, 2013 4:17 pm

I recently bought a 2007 Toyota Corolla LE and the check engine light went on a week after my purchase. I took it in right away and was told it was a faulty Mass Air Flow censor. I got it replaced and the light came on again 10 hours later. I took it back, they said it was the Mass Air Flow Censor, again, and they kept it for a couple days. Said I was good to go. The light came on again an hour later. I took it to Autozone to have it scanned and it said SYSTEM TOO LEAN. I called the dealer and they said maybe the air filter cover was not on securely, I lifted it and put it in the slots and back on completely and he said maybe it would go off after a number of "cycles" it is still on... What should I do?

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carriedi
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Re: 2007 Toyota Corolla Mass Air Flow Sensor/ System too Lea

Unread post by carriedi » Thu Apr 11, 2013 7:33 pm

you might try to see if there are any air leaks between the MAF sensor and the intake. or any vacuum leaks else where for that matter. Where did you get your replacement MAF? some recommend you get the OE for the best chance of getting the right performance. The lean code is when the computer looks at how much air enters the intake and it's programming says that a measured amount of fuel goes with that amount of air. The O2 sensor reads the exhaust and sees if the computer is correct. Too lean means the O2 sensor is telling the computer that it is not getting enough fuel to run correctly. so either there is a vacuum leak after the MAF, The MAF is reading wrong or there is a problem with the engine not getting enough fuel,
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ProTech
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Re: 2007 Toyota Corolla Mass Air Flow Sensor/ System too Lea

Unread post by ProTech » Thu Apr 11, 2013 7:35 pm

You should take it back to them and make sure they fix it correctly. They are obviously missing something, but since you've paid for a repair they said would fix the car, they should be on the hook to have to take care of you now. When the car is running lean, it's getting too much air, or too little fuel. This is normally due to something wrong in the intake path, such as your Mass Airflow Sensor. Vacuum leaks, or incorrectly installed air filters, lids and ducting can do this too.
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tufail123
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Joined: Thu Oct 30, 2014 12:10 am

Re: 2007 Toyota Corolla Mass Air Flow Sensor/ System too Lea

Unread post by tufail123 » Thu Oct 30, 2014 12:17 am

That is a sign of something drawing a lot of current. So, when you touch the battery cables, whatever is doing that is turning on or trying to operate. Check for a current draw with a test light, not an amp meter since that kind of draw will blow your meter, inline with one cable. This will show what is drawing current. Then you can start removing fuses until the draw goes away to find what circuit is hot.

toyomasterthing
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Joined: Mon Oct 05, 2015 4:25 pm

Re: 2007 Toyota Corolla Mass Air Flow Sensor/ System too Lea

Unread post by toyomasterthing » Mon Oct 05, 2015 4:33 pm

check code , they have been having problems with the intake gskt leaking. easy to find, while running hook up scanner and watch fuel trim and spray quick start around intake gskt. If yoy see the fuel trim drastically move that's your problem.

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