the EGR can be tested??

hello...
i want to ask you guys a question..

is there something to test an EGR valve??

is for a blazer TBI 90 4.3L .
because this things are a little expensive.. well, not too much. but i have to buy soe other parts.

and how i know if the IAC (idle air control) needs to be replaced??

thanks ..

Nalgman

Remove the EGR and apply vacuum to see if it will open and make it is clean of any carbon buildup.

The IAC also will have to be removed and cleaned up any carbon buildup blocking the port it inserts into and the valve itself.

Use throttle body cleaner and a toothbrush to clean both.