Check engine light again?

[LukeO]

1997 80 series, anyway the check engine light is on again, code again reads insuf EGR flow. I have replaced the EGR valve, modulator, EGR sensor and hose lines, but the same code keeps coming back. What gives?

 

[Junk]

Have you read the EGR faq?

 

[Scamper]

You might also want to check to make sure you routed the hoses correctly. Follow the FSM or EGR sticker under the hood.

 

[Rookie2]

If your going to through parts at it, VSV for the EGR would have been my first suggestion.


Rookie2

 

[Beowulf]

>> What gives? <<

As Rookie2 says, you're throwing parts at the code and not testing components before replacing. (FYI, I did the same thing.) In many cases, the VSV for EGR has been the failing part. Unfortunately this little part is in a hard place to get to. Since that's the only thing you haven't replaced, you can get to it from underneath the truck, then from above. (Read archives.) Follow Tom's advice to check the inter-connecting hoses first.

-B-

 

[Rookie2]

In many cases, the VSV for EGR has been the failing part. Unfortunately this little part is in a hard place to get to. Since that's the only thing you haven't replaced, you can get to it from underneath the truck, then from above. (Read archives.) Follow Tom's advice to check the inter-connecting hoses first.

-B-

FWIW, I haven't tried the underneath method, but I found it pretty easy to remove the VSV after the throttle body was removed (and long arms help). And that way you can give the TB a cleaning while it's off. How would you say it 'B'..., 10 birds with 1 stone??


Rookie2

 

[Andrewsreef]

Mine turned out to be the VSV (made the light go out anyway). However, as others have said, make sure you clean the passage/s on the intake plenum (what the throttle body attaches to) for the EGR. It is a hole/port about as big around as your pinky finger. Mine was clogged solid with carbon. Just a thought as I missed this passage when I did my VSV (because I did not read the excellent TB carefully enough).

Andrew

 

[tarbe]

LukeO

How long did your light stay off?

I replaced my modulator only about 3,000 miles ago and the light has not come back on.

Wondering if I am living on borrowed time?