EX4 - Exhaust Manifold Restriction

^ Remove the exhaust manifold(s). Inspect the ports for casting flash by dropping a length of chain into each port.

NOTE: Do not use a wire or light to check ports. The restriction may be large enough for them to pass through but small enough to cause excessive back pressure at high engine rpm.

^ Is the manifold free of casting flash?

YES -- RETURN to the Diagnostic Routines. Diagnostic Routines Index

NO -- REPLACE the exhaust manifold. GO to EG8. EG8 - Rerun Exhaust Gas Emission Test