RPM surge when coasting

[TurboRamNJ]

Ok, so on decel my rpms surge, they will jump about 400 rpms and drop to normal. 128k miles, and it just started doing it. I noticed that my AFR's will hang around 15-16 when this happens. Since Decel fuel shut off is active, it should be zero (lines). When it is zero, it decel's as it should. It happens a few times a day, sometimes worse than others. Anyone else have this issue? I was / am leaning on a leaky injector.

 

[caulk04]

Are you seeing the trans downshifting? The tune might just be throwing in a little fuel to match rpm and soften the downshift.

 

[TurboRamNJ]

Nope, same tune thats been in it for 3 years. I even reloaded the tune "just in case" lol and no change. Im feeling like this is a mechanical issue.

 

[Daw14]

Check your intake manifold bolts , they may be loose.