If it has never been tuned up, chances are that is the problem. Has the check engine light come on? As far as a tune up, I would estimate around 200.00. However, that can change based on where you live and labor rates.
I assure you, if the plugs are OEM with 175K on them, they have been done for a long time. They will cause a miss and backfire.
Let me know if you have other questions.
Monday, December 14th, 2009 AT 10:11 PM