where is the egr valve on a chevy 4.3 and how do i take it off on 1990 Chevrolet S10 Blazer

where is the egr sensor on a 4.3 chevy and how do i take it off/?

Asked by for the 1990 Chevrolet S10 Blazer
It's on the back of the intake on the passenger side. there is a bolt on the underside of the diapham. It might be cover with oil and dirt. I believe it is a 13mm.