1996 Pontiac Grand Am timing chain?

[quote:8478d56912="wandafb27"]Engine Mechanical problem
1996 Pontiac Grand Am 4 cyl Front Wheel Drive Automatic 90000 miles
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my husband just bought a 1996 or 1997 pontiac grand am. the owner says the 2nd and 4th cylanders don't work right. he has replaced almost everything except for the timing chain/belt. could that be the problem, and how difficult is that to fix ourselves?[/quote:8478d56912]the timing belt controls all you cylinders not just two. what did he exactly replace on it. this will give me a better idea on what it could be.