My 2003 santa fe is misfiring on cylinder 1. I need to know which coil is cylinder one so I can change out the coil?

I think you have an ignition module which may be bad.

Odd cylinders are on the firewall side of the engine.
Number one should be near the passenger side or front of the engine.

Got a check engine light? Get the codes read to find out if the misfires are on all cylinders or just 1. Could be ign coil, bad crank or cam sensor, or a valve issue

check ht leads coil.

Try shaking the ICM connector see if it effects engine operation if it does inspect for looseness and poor terminal contact,these have a know connection problem especially 1,3,6 connections these are known as (COP) coil on plug

Run a compression check , possible causes leaky valve seal, bad rings , bad headgasket

do tune up cap , wires etc.. also check coil for this cylinder,

The coil itself could be bad.
Try determining if there is a miss on a cylinder or cylinders.

i believe each plug has its own coil you need to verify which cylinder is effected alanwrench

This is a pretty common problem. I would change your valve cover gaskets. They run around ~ 50 bucks. If they are bad it will leak oil into spark plug well and cause a misfire. Very known on the 740.. Also if tune was not anytime not too long ago id change spark plugs while you at it. Then clear the computer and if you still get misfire on 8 try changing the ignition coil which is right about the cylinder with cylinder ignition coil 5. clear the computer. if you get random misfire and misfire cyclinder 5 after then its your ignition coil. parts store runs around 100 bucks