JDJP

iTrader: (2)

My SES light is on,just used the computer at advance and got two codes
DTC (codes)
P0446
EVAP emission
control system
vent circuit malf

P1416
Manfacurer contrl.
Auxiliary emission
controls

What do i need to do?

Thanks
JD

2001NBMZ28

When I had P1416 it was a clogged passenger side air check valve (the black disc shaped valve in between the metal pipe coming off the exhaust/then connects with a clamp to the air hose - just above the #4 cyl coil pack). GM PN is 12565503 but cheaper from a parts store, think I paid about $15.

JDJP

iTrader: (2)

I changeg my plugs a little while back. Is there any way to tell if the check is clogged?

jmm98LS1

iTrader: (28)

Rip all your emissions crap out.....that'll fix it.

2001NBMZ28

P1416 sets the light on the second consecutive cold start failure. If it's been a while since you changed plugs shouldn't have anything to do with it. It's easy to R&R the check valve, take it off and tap it on your bench - bet it's full of carbon deposits like mine was - if it is I'd replace it.

JDJP

iTrader: (2)

Thanks man,
anyone know what to do about the other code?