Quote:
Originally Posted by 67 chevelle
Most certainly , when a catalytic converter goes ,it does this but its full time , not intermittent , the diverter valve that runs gas to your air cleaner may be causing the issue ,
|
gas to the air cleaner? Are you talking about the flapper valve in the snoot of the air cleaner? I just checked it. That valve is fairly stiff and defaults to the open position (fresh air, not exhaust air). It has a vacuum port on it, but it was disconnected during the test. I just tested it with a vacuum pump. It's definitely broken. Does not hold vacuum and does not close. I don't see how this could be causing the vacuum drop during cruise speed as it was disconnected during the test, but I definitely need to fix it.