My check engine light has been on for the past month or so and the car has a pretty rough idle when im stopped in Drive, and the rpm's also jump around between 500 and 1000 rpm when in neurtal and my gas milage in the city is terrible I had the check engine light diagnosed and the code comes back as a Missfire. Ive had something similar happen in the past and I had my machanic adjust the idle air control valve and he also replaced a few vacume lines. But a year later and im back in the same boat. I was wondering if this has happened to anyone else and if they had any suggestions could this problem also be a result of a bad fuel injector? I had a problem with a few injectors and someone had told me (dont know if its true or not) that additives in gas these days are known to ruin the O ring seals around the injectors of older cars. Has anyone run into this problem? if you have, is it worth it to get new injectors or try and find O ring seals.

Thanks Guys

My 96 did that 3 weeks ago, just started missing out of the blue, I had it scanned at AutoZone and they told me cylinder #6 was misfiring, I put a new set of plugs and plug wires on it and it's purring like a kitten again.

If you got bad O-rings on the injectors you will certainly know it with your nose from the gas vapors you will be smelling! And O-rings are cheaper than injectors by a long shot (Around 20 dollars for an O-ring kit for all the injectors plus about 10 for an Intake Manifold gasket kit vs about 50 dollars or more for a single injector). If you do have to replace the injector O-rings be very careful removing the injectors from the fuel rail, the fuel rail is make of a bakelite type material, and if it gets cracked and or broken then you have real problems.