You may have to use diagnostics to tell the car the battery has been replaced, not sure on your model. AGM is not good unless the car was designed for AGM. Check the voltage at the battery with the engine idling.

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replaced the daughters( originally mine ) jointed under chassis rail but you will have to remove and cap pipes at ABS pump ( two different sizes but they are marked RL & RR on pump housing )and drain them as the flaring tool will not grip the...

may help

TRY

As you had the tank removed for the cross member replacement have you checked the fuel delivery pump filter in the tank you may have disturbed sediment in the tank and it's starving the pump