I have a 97 2.3L ford ranger and so far everything is good.

I recently change my air filter, fuel filter, timing belt, canister purge solenoid and sensor, egr valve and dpfe.
This day I could hear a strange sound coming from my exhaust... WHen idling, I suddenly accelerate and release the accelerator and I could observe 2 steps.

The first one when I accelerate, everythings normal but when I release the accelerator immediatly, I see the engine still high in rpms before lowing down while making a weird sound coming from my exhaust. I took the test while hood open.

The sound is like something vibrating inside the exhaust or like something clogged in the exhaust or just before the exhaust.
I don't know much in mechanic so could anyone help me please.

 

It's like the engine cough or something like that

 

If your truck had a misfire at one time, the catalytic converter could be clogged or broken up inside.
Let the truck cool down and crawl under it, hit the catalytic converter with your hand and see if it makes a rattling noise. It is right next to the transmission on the passenger side.