Exhaust System Backpressure
WARNING: This page is about a different car, the 1994 Plymouth Laser and 1994 Eagle Talon. However, it is still accessible from the selected car via links, so may be relevant.
Exhaust system can be checked using a vacuum gauge or pressure gauge. If using a pressure gauge, remove O2 sensor or air injection check valve (if equipped). Connect a 0-10 psi pressure gauge, and run engine at 2500 RPM. If exhaust system backpressure is more than 1 3/4 - 2 psi, exhaust system or catalytic converter is plugged.
If using a vacuum gauge, connect gauge to intake manifold vacuum port, and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for a restriction.