a high flow air filter would be a start, next find a super programer to fit that model, also exhaust cat back system would help. be careful, too much power will damage some thing when it goes beyond what the car was desighned for.
bad teeth on the mast, mast can be purchased seperately, make sure the electric motor is working though.
No. 2002 was the last year.
drop the fuel tank, it is on top. But before you do that, make sure your fuel pressure regulator is not the problem, probably is.
Proberly a miss fire in one of the cylinders.
theres a micro switch like hinge in the sterring colum that make it do that. replace and move on
Worn bands Dirty/burned fluid Plugged filter
Depends on which Cadillac model you're referring to...
You can get a wiring diagram for a 1997 Cadillac Seville STS at Wiring4Cars. The site lets you search for diagrams by year, make, and model.
First check the emissions label under the hood at the front of the car near the fan shroud. There is a large label telling you important information about your car. The gap for a 1976 Cadillac Eldorado with a 500 ci engine is .060 in. make sure to buy good quality AC Delco plugs and torque them to 25 foot pounds.
It depends on the motor im not sure if the eldorado ever came with a 4.9 but i know on my eldorado it was underneath the intake manifold...which involves taking the fuelrail off and is not something i would recommend doing by yourself if your not a mechanic but if you do make sure you change the injector o rings because leaking after this is common and can lead to a bad motor fire
Cooper Tires make the Eldorado Tire
The era gap is huge when considering a 1990 Deville to a 1997, no way is it possible unless you have tons of time to make extreme modifications and LOTS of money.