p2453 code will not stay off, what am I missing?

I have been trying to get this car to clear all codes so I can smog it here in California and without smog I can't transfer ownership so I'd like to figure this out asap.

This car had a failed hpfp so I never had it running before I fixed it. After getting it running the engine light was on so I cleared it not paying attention to any codes. Then the light came on immediately so I checked it and the code p2453 is the only one it had so I did what the ross tech website said to do, checked wiring and tubing, blew out the lines, the one differential pressure valve and connector was broken so I was sure that was the problem but after replacing them, the light comes on immediately and will come back immediately with the engine light coming on at the next engine start. I replaced it with genuine vw part. Everything seems fine but it will not stay off.

I am no expert with vcds, the only thing I really knew how to do with it before this job was to time my ahu and alh motors in my cars when doing timing belts and clear codes. This is the first time working on the cjaa motor and I learned that parts needed to be adapted when I changed the injectors on this motor and had to enter the code to adapt each injector. I assumed there is no need to adapt these differential pressure sensors but have been reading on the internet how some people say they have done it but I can't figure out how or if I need to do that, I don't see the part on the adaptation list. The part number of the sensor is 076906051B for both of them.

If you know what I need to do I would appreciate any advice that could help me. I feel like just getting rid of the whole cat and filter but that won't fly in California, everything has to be stock and functioning 100%. The car runs and drives perfectly otherwise, I am just about to hit 90k miles. Thanks in advance for any help.

Can you provide some information about the car? What year, how many miles, what model?

Check for boost leaks and properly operating MAF as well.

I guess that would be helpful, Its a 2010 golf, almost 90k miles all stock, automatic trans.

I found the solution to this problem, the new part needed to be adapted. I followed the procedure and it worked perfecty so for replacing those differential pressure sensor this needs to be done at least it needed to be done on my car. The procedure is in the ross tech wiki under exhaust gas differential g450 adaptation here:

http://wiki.ross-tech.com/wiki/index.php/2.0L_CR_TDI

it says this:

The Exhaust Gas Differential Pressure Sensor (G450) Adaptation is performed based on the EDC Protocol which is shown in the upper left corner of the Open Controller screen
CAN Protocol (G450) procedure

Instructions should be populated in a pop-up balloon when connected to the controller in question with VCDS.

Key ON, Engine OFF
[Coding-2] or [Login-II] button
Enter the code shown in the VCDS pop-up balloon
[Do It!]
Switch Ignition OFF for 30 seconds

After the key is cycled back on the adaptation should be completed. If it is not completed, proceed with the next steps:

These steps must be repeated 5 times.

Ignition ON
Wait 5 seconds
Ignition OFF
Wait 40 seconds
Repeat 4 more times

Great news. A question: Did you try to drive it with the light on? Like drive it 100 miles or more? Sometimes, codes will clear with alot of driving.

I drove it many hundreds of miles trying to clear that code, used several different sensors, switched them around but the only thing that worked was adapting the sensor and the light and all pending codes stayed off for good, it was miraculous.