On the 2.4 L the up stream O2 sensor is located in the exhaust manifold between the engine and the firewall. It has a single wire coming out of it. I believe it will be a purple wire. The down stream, heated O2 sesor is located under the car after the catalytic converter in the ehaust piping. It will have four wires coming from it.
Yes!
under the dash
Something...
usually on the driver side door
On a 98 Pontiac Sunfire, the red color of wire goes on the terminal marked "B" on the starter. This terminal is located close to the battery of the vehicle.
the 98 sunfire haz a 57.2 litre gas tank
150psi
I have a 98 sunfire with the 2.4L and it is getting about 35m/gal on the hwy.
Have a look at this web site; http://consumerguideauto.howstuffworks.com/1995-to-2005-pontiac-sunfire-6.htm FriPilot
This should help you out; http://consumerguideauto.howstuffworks.com/1995-to-2005-pontiac-sunfire-6.htm FriPilot
if you're going through the trouble of dropping the fuel tank, I'd just put a new one in and be done with it
it's getting too cool, really