2000 LINCOLN LS FAILED SMOG TEST

SOURCE: my 2004 lincoln ls is mission i failed my emission

I assume you mean MISSING, as in MISFIRING? That means your vehicle has 1 or more cylinders not correctly firing and using the gasoline to produce power. Likely this is accompanied by reduced power and mileage, shaking at idle or under acceleration, and a check engine light on solid or perhaps even flashing while you drive.
You need to have it fixed by someone who can diagnose the problem properly. I can tell you coils are a pattern failure, or injector harnesses corrode from water intrusion, or that the valve covers on those tend to leak causing arcing to the oil...but none of that matters to your CAR. whichecver of those, or something else...is causing the misfire is what you should fix. the cheapest, fastest, best way to find that is pay a qualified technician to scan for trouble codes and diagnose the results provided by those codes. Silver bullets and pattern fails can save a technician tyme or money, but if you can even provide code data or datastream analysis...the likelihood of wasting significant money with pattern guesses increases exponentially. Most shops will do a misfire diagnosis for a 1 hour labor fee, some include more extensive prove-outs and verification tests and charge 2 hours. Hope it helps.