98 2.0L DOHC no pwer in first gear idles rough.

[jfoesig03]

I have had my 98 Countor GL 2.0L DOHC for 6 years and have never had any problems with it. It has an automatic tranny. It has 160,000 miles on it now. The check engine light has been on for a couple of months. Three weeks ago while droving the acceleration bogged down and it started idleing rough. The timing belt was replaced 2 months ago. I had my father bring his code reader over and it said the camshaft position sensor was bad so i replaced that. made the problem a little better but not gone. so my dad again brought the code reader and nothing. so i replaced the plugs and wires. again nothing changed. The battery was also changed less than a month ago. My dad checked the catalytic converter and it appears to be fine. here is my description of the problem. when it idles it sounds like it wants to shut off at times. my engine shakes and vibrates more than before. it sounds like it's missing. when i try to drive it it is very slugish and has a puttering sound but only in first gear after it shifts out of first it runs fine. no power to climb a hill. and there appears to be more exhaust fumes. my dad and i are stumped at what it is. i can't afford to stab in the dark anymore and taking it to a garage is out of the question. please help me out.