Took my car to shop and said it is an ignition problem. Don't know the source but said I should not have used platinum 4s on my car. Is this bogus or what. Thanks

 

it has nothing to do with using platinum or copper tip spark plugs.

the platinum on it is just as small as a grain of sand, and only to keep the electrode life longer. everything else is of the same design.

if ignition problem...which cylinder is faulty?

try swapping the supressor plug and see if the defective cylinder changed.

also swap the coil.

it's just a few minute job since your engine is 104.