Engine turns over but dosent start ? 1997 ssei

If you have csfi, the fuel pressure is 60--66 psi, key on engine off.

Which O2 sensor ? Bank 1 sensor 1 or bank 1 sensor 2 or bank 2 sensor 1 or bank 2 sensor 2 . What size engine ?

Don't worry I'm sure you will get the solution of your problem, just check the link I attached 1997 Nissan sentra

This sounds like a "heat soak"issue(something is failing on a hot engine shutoff).The low tech solution I used to use often was a can of brake cleaner.Get the car hot,shut it off,and try to restart.If it wont,try spraying a quick burst of cleaner at various sensors(to cool them off) and trying to start it again.The most common sensor I would find as the cause was the crankshaft position sensor.(Sometimes a little tough to get at).

The Data Link Connector is located under the driver's side dash panel, by the footwell.

You mean the engine dosent turn or the engine dont start. If it dosent turn then try to turn it manually by a socket and ratchet in the crank pully bolt, I have changed the starters only to find out the engine is seased.

I assume you're referring to the heater core.Its located under the passenger side of the dash.I removed the passenger side seat and did it on my back.It took me about 4-5 hours as I had never done one before.The hose clamps(in the engine compartment side) are very difficult to get to without a special hose clamp tool.If you've never done it I say take it a good mechanic!

are your dasboard lights at full brightness?Turn your headlight switch(it may be on the interior light detent).BTW I drive a '97 Bonneville SE and one great thing about these cars is that if you leave a light on it will shut off after about 5 minutes so it won't drain your battery overnight.

a few pop pins and maybe a few screws not very hard to do

If you can get me the factory code I can get you the unlock code