@emsvitil

Thinking more about that baffle, have you tested with and without? I do not understand why the EGR would need back pressure. It seems like once the valve opens manifold vacuum would suck the exhaust right in, pressure or not. Or is there some sort of exhaust scavenging at work? (Bernoulli's principle?)

Not back to back.   I just squeaked thru a smog test, and the next time after I added the restriction it passed easily.    The lack of backpressure happens with a catback exhaust replacement...........

The modulator needs the backpressure.      I don't have my FSM at the moment..


Snowtoy,   show a picture of the modulator with the EGR valve.     I think you'll see that backpressure helps with the opening of the valve.

Or it's more backpressure helps force exhaust thru the valve..............