Exhaust System Backpressure
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1994 Plymouth Sundance, 1994 Plymouth Acclaim, 1994 Eagle Vision, 1994 Dodge Spirit, and 1994 Dodge Shadow. However, it is still accessible from the selected car via links, so may be relevant.
The exhaust system can be checked with 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 gauge, and operate engine at 2500 RPM. If exhaust system backpressure is greater than 1 3/4 - 2 psi, exhaust system or catalytic converter is plugged.
If a vacuum gauge is used, connect it to intake manifold vacuum, and start engine. Observe vacuum gauge. Open throttle part way and hold it steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restriction.