I'm trying to get my OBD2 LT1 car to pass Illinois emissions. It still has EVAP, but EGR and AIR have been deleted.

I can think of one obvious way to make them pass:
--Reconnect the AIR pump and its flow detector, and route it straight to open air.
--Pull the intake, reconnect the EGR valve and its solenoid, perhaps tapping off one my Mufflex's O2 bungs for the exhaust gas supply to avoid having to do any welding. This way I don't have to screw with fooling the MAP sensor when EGR gets tripped.

Nothing beats actually having the sensors there. But I can't help but wonder if there's a way to use relays and resistors to fool the PCM.

My main question concerns EGR. When it's enabled, does the PCM look for a simple change in pressure from the MAP sensor, or does it go so far as to calculate whether that pressure change is in-line with throttle position and RPM?

 

A TTT for ya.

I also would like to know more about AIR system readiness checks and how to fool them. I would like to remove my AIR pump to gain space for my upcoming blower install, but need to pass inspection station scans...

 

It is going to be hard to "fool" your PCM into thinking the AIR is working if you don't connect it back just like stock. When the PCM commands the AIR pump to come on it looks for a drop in O2 sensor voltage to confirm it is working properly. If it doesn't see the correct drop, you will get a code for AIR injection and won't pass the OBD check.

 

Just relocate the air pump.