1998 Pontiac Sunfire Gt Front View
1998 Pontiac Sunfire Gt Installing Header

Installing the header will be much easier if you have access to a hydraulic lift. If not, support the vehicle on jackstands. Disconnect the battery. Remove the oil dipstick and tube. Unbolt the heatshield from underneath the car.

1998 Pontiac Sunfire Gt Locate Oxygen

Locate the oxygen sensor wiring harness. Disconnect the sensor's plug. This is a lot easier than trying to remove the oxygen sensor from the exhaust manifold.

1998 Pontiac Sunfire Gt Support Cat

Support the catalytic converter with a stand. Separate the factory downpipe from the converter by cutting the pipe with a saw.

1998 Pontiac Sunfire Gt Begin Removing

Begin removing the exhaust manifold's and downpipe's fasteners. Some of these bolts and nuts are not easy to get to. Gain access to the nuts from both underneath and above the car, using 13mm and 15mm sockets. You'll also need a long socket extension to reach some of the bolts. Pull out the downpipe.

1998 Pontiac Sunfire Gt To Remove

To ease the removal of the manifold, move the brake booster vacuum line, the cruise control box, and the fuel line bracket out of the way. Pull out the manifold. Place it in a vice and use a special sensor socket to remove the O2 sensor. Install the sensor to the new RK header.

1998 Pontiac Sunfire Gt Install Header

Install the header from the top of the vehicle. Be patient. Because of the cramped engine compartment, it's not an easy fit. You'll have to wiggle around quite a bit to slide it in. Install the 10 header nuts, tightening them from the center of the engine block out.

1998 Pontiac Sunfire Gt Tighten O2 Sensor

Tighten the oxygen sensor and reconnect the plug. Replace the oil tube and dipstick, brake hose, fuel line, and cruise control box.

1998 Pontiac Sunfire Gt Using Springs

Using the supplied springs, washers, and bolts, connect the adapter pipe to the header. It will take quite a bit of pressure to compress the springs. Fit the adapter pipe into the catalytic converter (Auto Works recommends welding it).