A car catch can is an aftermarket device that captures oil vapor and contaminants from the engine's PCV (Positive Crankcase Ventilation) system to prevent them from entering the intake manifold, where they can cause carbon buildup and reduce engine efficiency. By intercepting these blow-by gases, a catch can helps maintain optimal engine performance, improve fuel economy, and extend engine life, especially in turbocharged or high-performance vehicles prone to such issues.
The PCV system is designed to recirculate crankcase gases back into the engine for combustion, but over time, oil mist can accumulate. A catch can acts as a reservoir, collecting this oil before it reaches critical components like intake valves. This is crucial for direct injection engines, where fuel doesn't clean the valves, leading to carbon deposits that can cause misfires or power loss. Benefits include smoother idling, better throttle response, and reduced emissions. Installation typically involves plumbing the can between the PCV valve and intake, with periodic emptying required.
For supporting data, here's a table based on industry observations of common engines without catch cans versus those with them:
| Engine Type | Carbon Buildup Incidence (Without Catch Can) | Reduction with Catch Can | Typical Maintenance Interval |
|---|
| Turbocharged Gasoline | High (60-80% of engines show issues by 50k miles) | Up to 70% less buildup | Empty can every 3k-5k miles |
| Direct Injection V6 | Moderate to High (50% by 60k miles) | 60% improvement | Check every 5k miles |
| Performance V8 | Very High (80% by 40k miles) | 75% reduction | Service every 2k-4k miles |
| Hybrid Engines | Low (20% by 100k miles) | 50% benefit | Inspect annually |
| Diesel Engines | Moderate (40% by 80k miles) | 65% decrease | Clean every 10k miles |
While not a mandatory upgrade, a catch can is recommended for drivers who push their vehicles hard or own models known for carbon problems. Always consult your vehicle's manual or a professional for compatibility.
