While like the title says, I was wondering if my bad gas mileage was coming from the fact that my ignition coils were crapping on me. They gave me a check engine light a while back, but hasn't done so lately, but could they still be bad? I've been keeping the RPMs under 4K and still I've only got about 50 miles for a quarter tank on premium gas. I'm going to have to trade the car in for a Schwinn if it keeps it up with gas prices in LA being $2.50/gal.

Are there any other issues that could drastically affect gas mileage? Maybe needing new spark plugs, need ATF change, etc? I got the used car at 65K so I don't have any idea on what service was done before that. I also think my trans is slipping...

Thanks in advance.

edit: It's at 75K now and only thing I've done is an oil change.

 

Gonna have to find a repair facility or dealership that has neccessary diagnostic tools for monitoring Oxygen sensors. Some that have 'slow' alpha readings have caused poor mileage in some of my customers cars.

 

Damn. Do you have any idea how much that is going to cost (to get it checked)? I'd replace them all, but I'd rather not spend $300 for coils if I don't have to (low funds).

Do you guys know how I could check to see if I need to change my tranmission fluid or my spark plugs? Don't know if it was done by the previous owner, and again, I'd rather not do it if I don't have to (esp if it was already done).