Head Gasket replacement - no start.

What is your question?

I have check timing marks: 1) Crank at TDC - Bank 1 and Bank 2 cams show "1" dot's aligned on exhaust and intake 2) Bank 1 and Bank 2 Cam pulley algined on marks I have photos of all poisitions. 3) Fuel and spark have been verified 4) Verified Cam sesnor wiring is correct 5) no DTC showing 6) vehicle turns over with starter and you will hear some pre-ignition in intake, which makes me believe timing is incorrect 7) Cams for bank 1 and bank 2 have been verified with lobe position for a firing order of 1,2,3,4,5,6

How long has your 2002 Toyota Avalon had this problem?

A few days