Help! Fuel Pump Misdiagnosed By My Mechanic
 

Hello,
After driving my car for the past 4 years, one day I tried to start it, but the engine would cut off after a few seconds. My car did not have any symptoms before this issue.
My mechanic tried to get error codes, but nothing appeared. He decided it was a failed fuel pump. I bought a brand new Volvo fuel pump, had it installed. The car still has the same issues. He is now recommending that the electronic throttle module needs to be replaced. After spending a small fortune on the fuel pump replacement, I am now hesitant to go with his ETM replacement recommendation.
However, I found the part here https://xemodex.com/us/product/elect...6001822-00-24/. Can you please let me know if this manufacturer is reputable? Would it be better to go to the dealer for this part?
Or would it be cost effective to buy the part here https://www.ipdusa.com/products/1062...le-body-module and have it programmed by the dealer?
Could there be other factors causing my car issues?

Thanks in advance for your help and input.