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I have a 07 6MT with 80,000 miles. I change my plugs every 30,000 miles with ngk's from the dealer and check the gap before I install them. I replace my air filter often, just did it approx. 5,000 miles ago. I have always used 91 octane since I bought it new. My problem has been going on for a while now, maybe a year or so, and is not getting any worse. When I accelerate harder then normal, maybe half pedal or slightly more, in any gear the engine pulls great/smooth then when I reach around the 2,150 rpm mark it boggs down a lot. It's very annoying when trying to gain speed on a on ramp or get ahead in traffic to make a lane change. When I am doing 65mph on the highway in 6th gear, throttle response is good until I give it about half pedal then I can feel it bogging again. I have never cleaned my MAF sensor. Any ideas
 

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Clean both air flow sensors. Be gentle I use electrical cleaner and canned air. Also might check your exhaust for leak where it mates to the y pipe. If that doesnt help you might wanna hook up to the computer and see if theres any codes


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I just had my yearly inspection last month, wouldn't any codes have been found when they hook up for the emission test?
 

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Depends on the mechanics. Some don't do a whole lot. It doesn't hurt to check. I have the wireless OBD that hooks up to my iphone to check codes and clear them. It could be nothing. Have you checked your throttle body (butter fly valve)? Doubt thats an issue but doesnt hurt to make sure its not filthy. Also try disconnecting the battery for 20 minutes. Other than that no sure what other trouble shooting you can do. It isn't a drive train issue and isn't a transmission. If there is indeed an issue I'd say either computer, intake system or exhaust
 

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It's funny this doesn't throw some kind of code, have you checked? I have same year with an auto. I clean my MAF sensor every 2 years and it clears a slight hesitation just off idle (specially when cold) but it never bogged badly like yours. I wonder if there isn't some kind of vacuum leak that prevents the butterfly inside the intake manifold to operate properly? This butterfly is closed to maximize runner length and improve low RPM torque and opens at high RPM to maximize HP by allowing a straighter shot of air though a shorter runner at high RPM. This is why normally you can feel a surge of power above 3000 RPM when accelerating. If it's not operating properly you may be getting too much fuel in mid-range causing the bog. Do your plugs show any sign of lean or rich mixture? I don't know how you'd check if the butterfly is operating normally. Heck I'm not sure it's even vacuum operated (just a guess.)
Maybe it's something in the VVT that's not operating properly? Was the oil changed regularly?
Last thing I can think of is clogged filter somewhere but you'd see a general lack of power, not just a bog. This is weird.
 

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I have the same obd reader they use at advance auto. I will hook it up tomorrow and also clean the maf sensor and report back. The bogging feels exactly like bad turbo lag. I always change my oil every 5 months or 5,000 miles, which ever comes first and always with mobil 1.
 

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Clean both air flow sensors. Be gentle I use electrical cleaner and canned air. Also might check your exhaust for leak where it mates to the y pipe. If that doesnt help you might wanna hook up to the computer and see if theres any codes


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I've cleaned my MAF near the air filter but where is the second one?
 

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on the y pipe
 

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I hooked up my OBDII reader and it shows no codes stored. I can't clean my MAF sensor today because it's below freezing outside and I don't like messing with cold plastic. So as soon as it warms up, hopefully sometime this week, I will clean the MAF and go for a test ride and report back.
 

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I doubt it could be your PCV valve, but it might be worth taking out and shooting some carb cleaner thru it. It's on the driver's side, rear of the engine.

Cleaning the MAF may help. Make sure you get the MAF itself and not just the air temp sensor, they are often confused.

Even if the throttle body were dirty it shouldn't affect things at the rpm you are experiencing.

Check all the air cleaner fittings, make sure they are tight.

A vacuum leak shouldn't be noticed much at that rpm.

If you have a fuel pressure gauge with a schraeder valve, you can check your fuel pressure.

Hope this helps.

DEWFPO
 

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If the pcv valve was bad you'll notice oil in your intake some blow by in side the butterfly valve.


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Also the reason fr resetting the computer is that its possible that its just tunes itself and optomized to your driving habbits


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Take it to a dyno shop and have it dynoed. Have them look for unusual Air/fuel ratios, or other potential issues. It should be clear as day on the dyno whats amis. Shouldn't cost more then 100$

Also check the fuel pressure at that rpm/load and see whats going on. you can do that yourself.
 

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I have a 07 6MT with 80,000 miles. I change my plugs every 30,000 miles with ngk's from the dealer and check the gap before I install them. I replace my air filter often, just did it approx. 5,000 miles ago. I have always used 91 octane since I bought it new. My problem has been going on for a while now, maybe a year or so, and is not getting any worse. When I accelerate harder then normal, maybe half pedal or slightly more, in any gear the engine pulls great/smooth then when I reach around the 2,150 rpm mark it boggs down a lot. It's very annoying when trying to gain speed on a on ramp or get ahead in traffic to make a lane change. When I am doing 65mph on the highway in 6th gear, throttle response is good until I give it about half pedal then I can feel it bogging again. I have never cleaned my MAF sensor. Any ideas
I know it is old , How you fix your problem! I just have the same problem that you had, please..
 

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The thread is 6 years old and the Original Poster who you quoted posted for the last time on May of 2013 that he sold his FJ.
 
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