Question about AFM

[iboughtatahoe23]

I drive a 2014 Tahoe with 175,000 miles on it. It was making a weird rattling noise when it was in V4 mode around 25 miles an hour so I got the plug-in disabler off Amazon and it stopped the noise and it keeps the vehicle and V8 mode so it can’t go into V4 mode to make the noise.

Anyway, fast-forward almost a year now still runs fine, and I recently did my plugs and wires, and I noticed that a lot of the plugs were running lean. They had white ashy tips. Some of them even had red brick colored ashes tips. And some had oil on the threads. I’m wondering if anyone here has used the plug-in and noticed this symptom or is it just a symptom of high mileage? Any suggestions ?

I will add I am the third owner on this Tahoe and no telling when the plugs and wires were last done I remember seeing the car fax one time and I should’ve taken a picture of it at the dealership

 

[Big Mama]

Other than the plugs is there any other sign that it’s running lean? What brand of plug did you pull out?

 

[iboughtatahoe23]

Other than the plugs is there any other sign that it’s running lean? What brand of plug did you pull out?

Not really sure other than the plugs.


And ACdelco

 

[iboughtatahoe23]

‍

 

[Chevymec]

If it was running too lean, the pcm should pick it up and throw a code.

 

[iboughtatahoe23]

If it was running too lean, the pcm should pick it up and throw a code.

Ya some thing strange going on. Idk

 

[Fless]

Your fuel trims would tell you a lot about how lean or rich it's running.

 

[iboughtatahoe23]

Your fuel trims would tell you a lot about how lean or rich it's running.

Noted. What do you think they should normally be. I have a scanner
that tells me that I tbink.

And if it is