Help! I replaced the head gaskets in my2005 Aztek and it runs good now but dies after a short drive and turning around in a parking lot.

I have checked all the vacuum hoses and replaced the purge valve solenoid. It was throwing a P0171 code ( bank 1 too lean) but I found a small fuel leak in the fuel rail and tightened it up and the code went away.

I am just praying that it isn’t something major, my wife loves the car and it only has 80,000 miles on it.