How do I fix my ignition timing on my 1997 nissan 200sx to pass smog, it's 41 btdc & it should be 8 btdc

something wrong here
with 99 degrees btdc it will not run
have you got it on the correct plug lead
next the timing is regulated by centrifugal advance if electronic or points and by the crankshaft position sensor if ECM controlled ( some after market distributors that are used in place of points units have a small sensor in the distributor that can adjust the timing according to engine rpms, but it cannot make allowances for mixture and so they can advance the timing but not take into account anything else which sometimes results in detonation under certain throttle settings
so initial setting for most cars is 10-12 degrees btdc at idle and with engine rpms set up to 3000 rms it may advance to 25-30 degrees depending on the advance mechanisms
with ECM units the timing is controlled by the crank position sensor and is set to parameters according to engine rpms and air/fuel ratio settings but it still has a basic 10-12 degrees btdc on starting
to fail smog tests you probably do not have a working cat converter and other problems besides timing

Have u already fixed the problem? disconnect the battery terminals

you will need a timing light to be able to adjust the distributor to make the timing 8 btdc otherwise you have no other way of checking it .

if they are getting carcon build up then you have a weak ignition control module and the wrong spark plugs . with the wrong spark plugs it is running and working hard

$100

I had got its manual from
online store www.reliable-store.com. Here's the site link I am sure they will help you

The only thing in the console is the Air Bag Module.

Yes, no problem.

16 Degrees if you have the 1.8L PFI DOHC 4cyl

If it was originally intended for Texas, it's probably been made as a 49-state-compliant vehicle (CA has stricter emissions). To pass in CA, you may need some new parts for the truck in order to get it to pass. Or you may find that the best course of action is to sell the truck and buy a CA-emissions car.

The CA DMV may well have information available on how to get non-CA-compliant cars to pass the CA emissions testing.