I recently bought a used '96 GXE with an odometer reading of about 118k (which isn't working, so it's probably more). So far I've had a corroded battery cable replaced, belts replaced and fuel filter replaced. It has a bit of a problem starting and sometimes it just clicks when I try to start it, but usually has no problem if I give it some gas (which shouldn't be needed). My mechanic mentioned something about the ignition itself, but that's not my main concern right now, I'm just establishing a backround (still need to have the ignition fixed/replaced, if that's the problem, as well as the spark plugs, various oils, coolant and air filter).

Anyway, the check engine light has been on since the purchase. I had a nissan dealer check it out and the report mentioned the absolute pressure sensor. After better educating myself, I discovered that I could get the ECU codes myself, which I did. Not only did I get back 0803 (Absolute Pressure Sensor), but I also got 0302 (EGR System Hi/Low Flow).

I bought the car for ~$7100, but still have the option of canceling the transaction...What can/should I do? Is it worth fixing? And how should I go about fixing it (nissan dealer/independent mechanic/myself)?