Question on timing belt for 1998 Taurus

My girlfriend has a 1998 Ford Taurus, with I think its a 3.0 liter V-6, could anyone tell me how often the timing belt should be changed ? and if it is a belt or a chain ? She is having a problem with it backfiring,, then running normal,, the Check engine light came on,, them went back off,, she has about 58,000 on the car and has had the oil changed regularly.. And advise on what it maybe would be great,,, And let me thank all in advance..

Dondo :)

Hi There,

According to my Ford dealer in Kansas City, it will be a chain. My Duratec DOHC engine has chains according to them and the other engine, the Vulcan is a pushrod engine which will also be a chain. Hope this helps and happy New Year!!! Can't help you with the other problems, sorry!

Ian