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Discussion Starter #1
Hi all,

Just got this 2009 Camry with 2.4 2AZ-FE engine, 5 speed auto and about 60K miles on it. It is getting about 14MPG. Although I drive mostly in the city, about 80% City, 20% highway, 14MPG (6KM / Liter) is not normal.

Everything works, I changed the engine with 5W-30 full synthetic, changed the transmission oil, and still pink. Also 4 brand new tires with 36 psi.

I haven't cleaned the MFA sensor yet, this is what I'm going to do next. I'm wondering if my O2 sensor is bad? There are 2 sensors, one in front of the engine which I can do it myself, another under the car which I'll need to go to a shop to do it for me.

P.S. I don't have check engine light on. And check engine light does work ( not blacken out by previous owner).



Many thanks!
 

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Hi all,



Just got this 2009 Camry with 2.4 2AZ-FE engine, 5 speed auto and about 60K miles on it. It is getting about 14MPG. Although I drive mostly in the city, about 80% City, 20% highway, 14MPG (6KM / Liter) is not normal.



Everything works, I changed the engine with 5W-30 full synthetic, changed the transmission oil, and still pink. Also 4 brand new tires with 36 psi.



I haven't cleaned the MFA sensor yet, this is what I'm going to do next. I'm wondering if my O2 sensor is bad? There are 2 sensors, one in front of the engine which I can do it myself, another under the car which I'll need to go to a shop to do it for me.



P.S. I don't have check engine light on. And check engine light does work ( not blacken out by previous owner).







Many thanks!


I thought the 2009 camrys took either 0w-20 or 5w-20?


Sent from my iPhone using Tapatalk
 

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Discussion Starter #3
Yes, I'd use 0W-20 next time, but using 5W-30 shouldn't give me such horrible gas mileage.

I used 30 weight because I thought it would give the engine a bit more protection. Definitely will change it to the correct 0W-20 next time.
 

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Discussion Starter #4
I went to a shop that has OBD II scanner, they didn't have one that read the Air-fuel ratio, but there are no code that says o2 sensors are bad. No check engine light. They gave me a suggestion, only a guess.
 

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08 Toyota Camry 2AZ-FE R9K Tuned
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I did. Twice.
You could change the 02 sensors to see if that changes anything or even unhook the battery for a bit and allow for the ECU to reset. Can't say if those will help. I've noticed a slight decline in mpg but at the same time not so much. Apparently the tune might've helped me but I never kept track of previous mpg.
 

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Discussion Starter #8
You could change the 02 sensors to see if that changes anything or even unhook the battery for a bit and allow for the ECU to reset. Can't say if those will help. I've noticed a slight decline in mpg but at the same time not so much. Apparently the tune might've helped me but I never kept track of previous mpg.
Thanks. What is your current mileage?
 

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Sorry, I meant your gas mileage. What is your MPG?
Generally speaking, what I've noticed when I fuel from E (gas light) to full TRIP B is at maybe 360 miles or less but it's not something I kept track of. I've got a tune that uses 91 octane and mpg it seems to have increased by a little bit.
 

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Welcome TwinCam2!


First off, the engine was designed for 5-30 so using it is perfectly fine and will not impact the mpg (0-20/5-20 is a nod to CAFE standards). 14 mpg is not normal , not even close. Can you give us a run down of when it was performing normally and if anything changed?


I am pretty sure my A/F sensor (O2) is going, as I will get running rich codes time to time and when I do my mpg drops down to 23 or so. Normally I get around 28 with mostly highway miles. But I do nave a new rebuilt engine in it (around 10k miles on it) but I always got around 28. The point is maybe your O2 sensor is causing a rich condition. Never a code at all?
 

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Discussion Starter #13
Welcome TwinCam2!


I am pretty sure my A/F sensor (O2) is going, as I will get running rich codes time to time and when I do my mpg drops down to 23 or so. Normally I get around 28 with mostly highway miles. But I do nave a new rebuilt engine in it (around 10k miles on it) but I always got around 28. The point is maybe your O2 sensor is causing a rich condition. Never a code at all?
When fully filled up, the computer says the cruising range is 323 miles. Definitely something is wrong. I just got this used, so I don't know why the previously sold it with such low mileage.

No check engine light, no code when scanned with OBD II scanner. The guy at the shop guessed it's O2 sensor.

How do you know yours is going? What code do you get? Has the check engine light ever on?
 

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Get a tailpipe emission (smog) test done. High hydrocarbons and/or high carbon monoxide confirms a rich fuel mixture or worn out catalytic converter. If emissions are low then oxygen sensors are fine and something else is causing high fuel consumption. Such as: low transmission fluid level (most owners can't be bothered to read and follow factory manual fluid checking procedures), aftermarket spark plugs (usually come with overly wide gaps), dirty MAF sensor, dirty air filter, dirty throttle plate, non-stock tire and wheel sizes.
 

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2010 Camry
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Do your brakes feel smooth or does the car pull to one side? Maybe you have a caliper hung up, applying the brakes all the time. To get a drop in mileage that much, I think you would be smelling brakes.
 

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Discussion Starter #17
Do your brakes feel smooth or does the car pull to one side? Maybe you have a caliper hung up, applying the brakes all the time. To get a drop in mileage that much, I think you would be smelling brakes.
No, I don't smell brake, and the car runs fine.

Could also be a bad thermostat... Seems like an O2 sensor would be throwing a code.
Water temp is normal. A/C and heater work fine.

Would a dirty MAF sensor give such horrible gas mileage? Wouldn't it also trigger the CEL?


I changed the transmission fluid when I got the car, along with the oil change. The fluid level is okay and looks pink. But I noticed something weird today, sometimes it does not shift to 5th gear when under 50MPH (i.e 48MPH). But sometimes it does.

Around 45-49 MPH, the engine rpm is 2K sometimes, and 1.5K sometimes (apparently 5th gear).


I only did a transmission fluid change, didn't do a flush, or transmission filter changed. Could it be that?
 

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How are the plugs?

Look for a large gap.

I had bad mileage years ago from a saturn and pulled the plugs to see that the gap was waaaaay too wide. I had set them right to begin with, but these things burned so hot that they had burned away a bunch of the metal of the electrode.

I now only use OEM plugs. Never trust what a parts store lists as OEM. The real ones are designed to fire at the right temp and most parts stores don't take that into account, they only worry about which threads will fit.
 

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Discussion Starter #19
How are the plugs?

Look for a large gap.

I had bad mileage years ago from a saturn and pulled the plugs to see that the gap was waaaaay too wide. I had set them right to begin with, but these things burned so hot that they had burned away a bunch of the metal of the electrode.

I now only use OEM plugs. Never trust what a parts store lists as OEM. The real ones are designed to fire at the right temp and most parts stores don't take that into account, they only worry about which threads will fit.
I haven't checked them, as I'd have to bring it to the shop to check for me. I don't have the proper tools to pull them. But for this mileage, I think it would have to be stock, and the previous owner never touched them.

If the plugs are too wide, wouldn't it idle rough or run rough? The car idles fine, run smooth. I'm suspecting during low speed driving, it doesn't shift to 5th gear as much as it should.

When is it supposed to shift to 5th?
 

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Discussion Starter #20
I may have found the problem... I looked at the fuse box, and the diagram, it seems the fuse for "A/F" is missing. It's 20A. I don't have a spared 20A fuse, so I'm going to get one from the shop.

The spot where fuse for "A/F" is missing. I don't know if it's supposed to be like that or the previous owner forgot to put it back. What if it's not supposed to have a fuse there, and I put one in? Will it damage anything?

What is this A/F fuse? My guess is Air/fuel sensor. Can you look at yours in the engine bay, is yours there? It's 20A yellow fuse.


Thanks.
 
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