I have been combing the forum for how to fix this problem but the threads are incomplete or say the sound was normal.

So my car has been running fine, no check engine light. I was testing my coils and wires with the HEI spark tester to see why my STFT goes all over the place when I accelerate or decelerate while shifting.

After, I was checking to see any pending codes. I ended up hearing a buzzing sound from throttle body. I unplugged something on it, then it got quieter but changed to a chirping Morse code. Then codes popped up P0123, P0223, P0302, and the system too rich code. I think the system too rich code is from the testing.

I got the misfire right after testing. I made sure the wires are in the right order and I made sure to separate the wires more. I'm pretty sure the misfire code will go away after a reset since it wasn't happening before.

I am more concerned with the TB codes and how to fix them.

 

The STFT is supposed to be all over the place while you're giving inputs to the engine. That's its job. It will be stable when you're holding the engine stable.

The throttle body is supposed to make sounds when you turn the car on and off, it's calibrating itself. The codes you're seeing sound like they have something to do with you unplugging things. Put it all back together, go for a drive and see the codes pop up again.

 

My STFT range goes from 21-22 to negative 20-25. It seems a bit strange to me because on my torque app it didn't vary that much before. I have a new BHR ignition, wires, and plugs. I tested because my LTFT also runs a bit rich. It fluctuates between negative 3.1-5.5 at idle, at speed it's at 0. Before one of my oem coils died the LTFT was -1.6.

I'll do that and let you know. I hope it's just me being OCD about everything. Thanks.

 

Yes. Fuel trims are not a fixed number.

 

I understand that they are not a fixed number. I have watched my fuel trims for awhile now. They were both pretty stable and close to zero until recently that's why I started to check out stuff.

I cleared the codes and they didn't come back, I still hear that noise and it gets louder if you leave the key on awhile lol. Oh well. Thanks.

So I let the car idle after the drive and the LTFT started to become more negative. I'd hear a sound then it would drop a point or two. It got to negative 13.3 then I turned it off. Even at a constant speed with cruise control the STFT will fluctuate between pretty high numbers. I normally don't sit at idle very long. I warm up the car by driving it under 3k until warmed.

Do the fuel injectors tend to go bad on these cars? My 2007 has 108,000 miles, my only other reference is a 99 Maxima that had the original fuel injectors until the pintle cap cracked off one of them at 262,000 miles and gas was pouring out the tailpipe kinda.

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Hmmm. Can you record the throttle body sound and share?
No particular problems with injectors but anything is possible.

 

Sorry if the video isn't professional, I just got the sound to be captured. The key is turned to the on position.


So about my LTFT going so negative at idle, I was reading that there might be an issue between the MAF and an O2 sensor or possibly a leaking injector. My MAF has been cleaned less that 700 miles ago, and I just cleaned the ESS and even tried to put in another used one plus tried to reset and battery disconnect each time. Do you think an injector leaking is likely because when accelerating and on the freeway the LTFT goes to 0. I will take the car and drive it like I normally do, which is usually the car on the freeway and I only hit like one light on the way to work, if the LTFT at idle speed works its way back towards 0 could that then confirm that an injector is leaking and shows up most at idle and is masked by not really idling too long? Not really sure how to test the O2 or MAF. With no codes this is kinda frustrating lol.

 

Whoa. That's a strange sound. It sounds like the throttle motor is trying to move the throttle past its stop point.

Does pressing the gas pedal vary the sound at all? May want to disconnect the intake and have a look and the throttle movement. Especially when you turn the car on and off, it's supposed to do a calibration cycle.

 

I'll check that later on, I just came back from a drive and as soon as I backed out of the garage the STFT was going to -25 and eventually the LTFT went to -22. So when I would push the gas light to medium pressure the STFT would pretty much go to -25 on the freeway. If I pushed it harder it would go to closer to 0. When I got off the freeway onto the main road back home the check engine flashed for misfires. The idle will be okay for awhile then kinda hiccup and shake a tad when I stopped but it didn't seem that bad.

I pulled pending codes P0411, and the one for system too rich while at target, when I got home I only saw P0411 and P0302 pending.

Could I have kIlled an already dying cat due to testing the coils with the HEI spark tester? Now I'm not sure if its the cat, fuel injectors, Throttle Body, or the MAF and O2. My MAF at idle when warmed up also seemed a bit higher today at 7 rather than 5ish.

 

usually TB issues are more drivability related than fuel trim. You should probably be focusing on the fuel system; fuel pump or injectors. Of course that assumes free flowing exhaust and properly functioning ignition system.

Understand there are multiple LTFT load zones; idle, cruise, etc. So it just depends on the rpm and load. You seem to be talking generalities with those specifics and those specifics do matter for determining and resolving the issue. I haven’t reviewed them for a while and need to go back and re-familiarize myself with them actually.

 

Haven't had time to remove the cat yet. My coils plugs and wires are fairly new, only about 700 miles on them. My fuel pump was replaced about 1500 miles ago by Mazda.

My references for the trims were at idle and cruising at 65. They were very stable and 0 at cruise fwiw.

I took off the intake and the flap cycles with the key on and off. Also moves when I push the pedal about 1/3 of the way down. IDK if that dead area is normal. If I press the flap with the key off, I can close it a bit more? With the key on and if I put a bit of pressure the noise gets a bit louder.

 

Here is a video made with how it moves with the key on and off and then pressing the pedal.

 

I disconnected the battery and did the 20 brake stomp before I changed back to the old ESS and cleaned up the TB a bit while I had the intake off. I made sure the screens were nearly perfectly aligned.

I took a short drive and then I got code P0113, first pending, then confirmed at home, the funny thing is that the car was running pretty well. The LTFT after only went to 1.6 and stayed at 0 while cruising. I'm gonna drive the car to work tomorrow and see if it changes anymore. It has never ran lean like that, always a bit rich.

This car is driving me crazy! I'm not sure what to make of this now.

 

P0113 is the temperature sensor inside the MAF. Did you plug in the MAF?

If not, there's an electrical problem in the MAF line. Potentially related to the throttle whine. I would check the wiring for damage as far as you can see it. If nothing, see if a new MAF fixes it but that's not my favorite solution.

The throttle whine could be related to the same electrical issue or have its own special problems. See if you can get another throttle body on the cheap or to borrow, to see if it makes the same sound in your car.

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I had kinda already half *** checked the wires near the TB to see if the sound would lessen or stop if I moved the wires a bit. The MAF was plugged back in after I put the intake back on. I reset the code just in case it was triggered from turning the key on with it unplugged. I'll need to drive around more to see if any codes come back. I am trying to find a TB to test quickly. Thanks for your input thus far!

I noticed something super strange today, I was checking for pending codes with the key on and if I move the shifter from neutral into gear the buzzing becomes more prominent. Do you think the neutral safety switch could actually cause the sound in the TB? Tomorrow I'll probably get under there and unplug it with the key on and in gear to see if it changes the sound.