I have changed both the pump and the valve and still get P2440 code aftre a couple days 08 Trailblazer

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1. Using a scanner, turn the Key On Engine Off (KOEO).

2. Check for a baro reading from the AIR pressure sensor of about 100 kPa (or 14.7 PSI)

3. Start the engine, turn on the air pump and the AIR control solenoid valve. This will measure the pressure from the air moving through the system into the exhaust. Expect to see 8-10 kPa higher than the KOEO kPa reading (or 1.16 to 1.45 PSI higher than KOEO PSI reading).

4. With the engine running, turn on the air pump, but shut off the AIR control solenoid valve. (This is basically a dead head test of the air pump). Expect to see 15 to 22 kPa above the KOEO baro reading (or 2.18 to 3.20 PSI above the KOEO PSI reading).

That code is related to the Secondary Air Injection System (SAIS) switching valve being stuck open. This valve is located on the passenger side of the engine mid position.

Put the OBD P2440 into Google for the answer

The valve may need to be replaced. Only air flows thru the components.

P2440 refers to the Secondary Air Injection system. It means that the switching valve is stuck open. We already replaced the secondary air flow pump, now it's telling us that's its the secondary air flow sensor and the valve is stuck open. the code is coming up P2440

P2430 Secondary Air Injection System Air Flow/Pressure Sensor Circuit,
The AIR diagnostic uses 3 phases to test the AIR system:

DTCs P0411 and P2430 run during Phase 1
DTCs P2430 and P2440 run during Phase 2
DTC P2444 runs during Phase 3
During phase 2, only the AIR pump is activated. The solenoid valve is closed, this is p2430 and p2440. -The AIR system pressure sensor is stuck. good-day !!

P2440 not P02440 !
P2440 Chevrolet Impala Air Injection Check Valve

P2440 Secondary Air Injection System Switching Valve Stuck Open Bank1

Problem is usually the air switching valve that operates the air line coming from air intake to air pump, clean it or replace it.

Here a bulletin.