u/Correct_Avocado_7888

▲ 3 r/CX5

Mazda CX5 rpm fluctuates in D or R

Problem is idle RPM fluctuation and slight engine shudder in D or R when the vehicle is stationary with the brake pressed (creep condition) - AC and all other consumers are off.

The problem started after intake manifold and EGR cleaning.

Symptoms:

* The problem occurs only in D or R when the vehicle is stationary with the brake pressed (creep condition).

* When the engine is cold, there is noticeable hesitation/shudder and unstable idle behavior.

* The issue disappears completely once the engine is warm.

* In N or P, the engine runs perfectly smooth at all times.

* Slightly increasing RPM (~1000+) immediately eliminates the problem.

* No fault codes are present (OBD is clean).

Work already performed:

* EGR and intake manifold cleaning

* Injector learning/recalibration procedure completed

* Transmission relearn/adaptation reset performed

* EGR reset/adaptation procedure performed

* Injector corrections are within -0.5 to +0.5 on warm idle.

Despite all of this, the issue persists under the same conditions.

My question is:

What could cause this type of behavior that appears only in cold D/R idle conditions after EGR and intake cleaning, even after all relearn and reset procedures have been performed?

Any guidance would be appreciated.

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u/Correct_Avocado_7888 — 6 days ago