Exhaust System Backpressure
The exhaust system can be checked with a vacuum gauge or pressure gauge. Remove O2 sensor or air injection check valve (if equipped). Connect a 1-10 psi 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 a vacuum gauge is used, connect it to manifold vacuum. Start engine and observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, exhaust system should be checked for a restriction.
ENGINE COMPRESSION SPECIFICATION
| Application | PSI (kg/cm2 ) | |
|---|---|---|
| Normal Compression Pressure | ||
| Pickup (22R) | 171 (12.0) | |
| Tercel | 185 (13.0) | |
| Minimum Compression Pressure | 142 (10.0) | |
| Maximum Variation Between Cylinders | 14 (1.0) | |