code 33 on '93 Mustang

[4-timer]

which is an EGR valve not opening properly. When I put 5+ vacuum on it it stumbles a bit but the diaphragm stays open and the vacuum holds. It appears to have some vacuum in the line when idling, but does not increase when I snap the revs to 2500. Does that point to a bad EVR solenoid?

[TENGRAM]

which is an EGR valve not opening properly. When I put 5+ vacuum on it it stumbles a bit but the diaphragm stays open and the vacuum holds. It appears to have some vacuum in the line when idling, but does not increase when I snap the revs to 2500. Does that point to a bad EVR solenoid?

The EVR solenoid should only apply vacuum to the valve under load, so no increase when free-revving is to be expected.

An inoperable EGR valve should not cause any performance or driveability problems. I personally would just leave it alone unless you're worried about passing emissions.

[garycrist]

This might help...........

http://sbftech.com/index.php/board,20.0.html

[4-timer]

This might help...........

http://sbftech.com/index.php/board,20.0.html

thanks.... great info here......