catalytic converter

I have a 1998 honda civic with 1.6 engine and 150,000 miles. Recently an engine light came on and i has it tested. The local firestone said that the problem is my catalytic converter. They also want to replace my front and rear exhaust pipes. I have to wait about 2 or 3 months to have money for them to fix this problem. The mechanic said I could go 20 years without noticing a problem. My question is will this problem effect other parts of my car? If so, what parts and how soon should i get this fixed to avoid those problems? thanks.