Code 28: Air Leak
Check for air leaks in following areas:
- Mass airflow sensor to plenum hose.
- Breather system hoses to plenum.
- Brake servo hose.
- Vacuum reservoir hose (fresh air solenoid).
- Distributor vacuum advance.
- Purge valve to plenum hose.
- Injector seals.
- By pass air valve to plenum.
- Plenum chamber to ram housing.
- Ram housing to inlet manifold.
- Inlet manifold to cylinder head.
- Bypass air valve hose.