EMC code 32 when driving faster than 50 mph

[BoK5]

I have a 89' K5 Silverado Blazer 4WD with an OHV 8V 350 cid engine, TBI and automatic transmission.


The 'Service Engine Soon' light comes on when driving 50 mph or faster for more than 5 minutes.
Driving at 40 mph or below I can keep driving without the 'Service Engine Soon' light comes on at all.
From the EMC I get a code 32.
My manual gives this explanation: Replace EGR valve.


I have unmounted the EGR valve and checked the membrane by compressing it and holding a finger on the vacuum inlet. First when removing the finger from the vacuum inlet the membrane returns to its start position. So to me I it operation OK.
I have checked that the EGR solenoid and it gets 12V, when ignition is on.
I have replaced the EGR solenoid with a new one.
I have disconnected the negative cable on the battery for resetting the EMC.
But the problem (code 32) is still happening, when driving 50 mph or faster.


Anybody have an idea to what I am missing...

 

[brans87]

Think I have same problem but need to scan it again. only comes about same speed as your talking and replaced it all!

 

[dyeager535]

Since you removed the EGR, did you notice if the passage was clogged with carbon?

I think you will have to register to see the image, but this post has "how" the code is set from the GM service manual: http://www.gearhead-efi.com/Fuel-In...95-TBI-EGR-code-32&p=3551&viewfull=1#post3551

 

[BoK5]

Inside the EGR valve the passage was not clogged with carbon. Actually it looked very fine. I have not looked inside the holes in the engine.
I have looked at the link, but the $42 hack is a bit out of my knowledge. But I did get the TBI manual in pdf. Thanks a lot, it has good descriptions on how to test in case of EMC trouble codes.
I will do the testing, when having got a vacuum pump and some time.

 

[dyeager535]

Good luck, keep us updated as you make progress!

In all honesty anymore, I don't see the need to even have EGR functional unless you have to pass some emissions test, but it requires a new PROM to get rid of it.