fuel pump problems on 2001 Bravada.

What is your question?

Myional miss, brothers Bravada will start and idle with an occasional miss, but will return to idle. Comp. says he needed an O2 sensor and plugs. He replaced these but when he puts the vehicle in drive it will not even pull out of garage, he was told fuel pump but what could be the most obvious problem or do u think fuel pump.