Found a huge vacuum leak. Probable cause?

[KBScobravert]

Working on the funds for a dart 363 so anything I buy now will be helpful later on.

But I get what you're saying.

I was more worried about crankcase pressure at high rpm. A lot of things I've found and read say one of the most important things to monitor is pan vacuum.

Then the oil fill cap will be your least expense. Seal your crankcase back the way it was meant with a PCV system.

Here is a simple test. Put the cap back on then tell us what the difference is in your AFR.

[Diabolic]

It doesn't read lean at wot because adpative learning it bringing it back to stoich. INteresting that it reads lower 14's instead of 14.5-15.3 during cruise and idle because as stated before, the wb displays AFR but really uses Lambda. The 14.67 for stoich is a mathematical equation programed into the wideband as the output valve for a stoich of 1. The only way to change this would be to go into the Logworks and change the value for stoich and all the other values in the range by the appropriate amount. Doesn't matter if you run E10, E85, VP116, or 100% gasoline.....your wb will still show 14.67 in closed loop unless the adaptives are unable to bring it back to stoich, in which case if will go into open loop and what you see on the wb is what you are really running. Clear as mud? Now you can have a breather on the VC or a PCV but not both.