How do you set timming on nissian sentra 2002 were do the mark go i took head off now need to set timming

Hi Richard. I'm Tim Dorton. Make sur the engine is at TDC #1 cylinder on the compression stroke. Crank over by hand with spark plus out, thumb over #1 cylinder hole, feel compression. Then put in #1 cylinder spark plug hole a thin screw driver, watch bottom mark line up and screw driver will reach highest point. then match marks to diagram.https://ww2.justanswer.com/uploads/indytech/2010-09-30_110635_Picture1timing_chain_1.6.png

need to find the timming marks and go from there

Unfortunately, replacing a sensor only fixes the problem about half the time. The code means the computer is not getting a signal from the sensor, not that the sensor has failed.
The problem could be in the wiring, or the part that the sensor gets the signal from.

If you have a multimeter, set it on x10 ohm scale. read resistance between engine and body, then negative terminal of battery to body. should be zero ohms. if not connect a ground strap from engine to body (make sure metal is clean at connection points) then one from negative of battery terminal to body. check again with meter should be zero ohms.

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

didnt you mark it before you removed the old belt??

1. Disconnect battery negative cable.
2. Remove power steering and air conditioning compressor drive belt by loosening power steering fasteners.
3. Remove generator bolts and generator belt.
4. Remove water pump pulley.
5. Remove crankshaft pulley and timing belt guide plate.
6. Remove upper/lower timing belt covers.
7. Turn crankshaft clockwise until "I" mark on intake camshaft pulley and "E" mark on exhaust camshaft pulley align with marks on cylinder head cover.

TIMMING BELT MARKS
NEED MORE INFO ON ENGINE 4 CYL OR 6 CYL
ALSO IF YOU JUST REPLACED THE HEAD ASSEMBLY MEANS YOU BENT THE VALVES WHEN THE BELT BROKE. TIMMING MARKS ARE DIFFERANT ON MANY MAKES PURCHASE A CHILTON MANUAL FOR THE YEAR AND MAKE OF YOUR CAR THESE MANUALS ARE GREAT AND TAKE THE GUESS WORK OUT OF THE TIMMIMG MARK ISSUE

timming marks on cams face each other 3 and 9 o clock crank mark at about 6 o clock mark in cover and sump auto adjuster arrow should be in v mark to set this requires turning water pump by loosening water pump bolts slightly be warned some times this causes pump o ring seal to leak if turning.

you cant without proper computer tools

Look for air leak either at the MAF sensoor near the carbon canister It cannot give correct reading when there is an air leak
Check emmisions
Regards
nik (Slowmeup)