I have a 98, 2.5L Duratec V6, 120K miles. Check engine light comes on. Dealer pulls code, it is "intake manifold runner control" fault. Total bill, including diagnostics, would be $387.50, not counting Pennsylvania tax.

Can I save $400 and ignore this? What would likely happen? Would I likely fail Pennsylvania emissions testing (due in April 05)? What does the runner control do?

Thanks in advance.