CEL and EGR code 34

Mike Puckett

SCCoA Member
Ever since I R&R'ed my right side cyl head back in August I've been plagued with a check engine light and get a 34 EGR valve not operating code. This past weekend I pulled the EGR valve back off and checked and rechecked it. Indeed, the valve opens and closes normally with vacuum or pressure. It's not plugged up nor is the intake manifold connection. I checked the resistance of the new canister, same as my other, and replaced the hose down to the EGR tube. I also resealed the EGR exhaust tube connections. But, alas, I still get a CEL. It doesn't seem to affect performance and when I had my emissions test everything was good. My NOx was about 600 out of a max of just over 1056 max allowable and HC was just under 50ppm so the EGR system appears to be working. I'm about to either just live with it or have my tuner turn off the code. Has anybody else run into this and if they cured it, how? I'm wondering if I have a wiring harness problem since it's been off and back on too many times. I used to be able to clear the CEL by unplugging and reseating the big square connector at the back rightside of the harness but it no longer responds to that.
 
Sorry, not sure about the EGR. I'd try and see what you are getting at the EEC-IV wires. It does sound like a wiring issue.
 
>and replaced the hose down to the EGR tube

What material did you use?

Have you checked for vacuum leaks, such as the valve cover gasket, PCV etc....
 
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I used a new silicone hose I had that came off of a 94 EGR valve. I thought that maybe the old one was collapsing. I'm still thinking I've got a wiring problem. I've got a pinout of the EEC and easy access to the plug so I'm going to take some measurements off there. I was just wondering if anyone may have run into this before.
 
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