EGR delete w/o PCM Flash

[GP98GTX]

Alright.. I've done a 3400 top end swap in my 98 GP with a 3100 block.. EGR's are different and my Chilton wiring diagram only lists the colors of the wires that are leading to the EGR connector.

..................................................... - ...................... +
They're labeled on the EGR as follows: ..A.... B...... C.. D... E
Wire colors are:................................ R.. BR/W.. BR. GY. GY

I cut the 'E' Gray wire and no longer have MIL codes for EGR low voltage but still have EGR codes for non-op. The manifold port is blocked and EGR tube cut. Having the 'E' wire cut disables the coil inside the EGR.

I am asking for any input to find a way to fake the computer into thinking the EGR is still operating with out having to flash the PCM. Any ideas?

 

[KeithGTP03]

If you find that out, let me know. My codes are tuned out, but I cannot pass inspection because it never completes its test and shows "not ready". Matt had told me that if I connect a wideband output to the EGR position wire, it would trick the comp into thinking its functional. I haven't had a chance to try that.

EDIT: Just realized I skipped your entire first paragraph. Not sure if this will work on a 3100

 

[GP98GTX]

Well I took a simple On/Off 2-pole switch and wired it in series on the 'E' Gray wire. Might not be the right way, but it's working 'right' now..

Before starting the car I flip the switch 'ON' to close the loop and let the computer run the start test, once driving >30MPH I flip it 'OFF' and haven't had a code pop up yet (Only when I forget to initially turn it 'ON')..

*I will continue to play around with the wiring and check the local GM dealerships/service shops to see if their repair manuals have better wiring diagrams.*

 

[BillBoost37]

If you delete the codes in the computer then you typically should be set. Another item to do is set the EGR minimum test temperature to the max setting. In HPT it's 284F. That keeps the test from ever needing to be run.

I have verified this works.

 

[GP98GTX]

If you delete the codes in the computer then you typically should be set. Another item to do is set the EGR minimum test temperature to the max setting. In HPT it's 284F. That keeps the test from ever needing to be run.

I have verified this works.

Thanks for the suggestion, but this thread is titled "EGR Delete W/O PCM Flash"

>>Also the OBD computer does a run-up test under initial engine start and without a complete circuit it will pop a code and illuminate the MIL<<

 

[CrazyGuy03]

Well if u want to delete it so it's not putting exhaust back into the intake use a block off plate. Block off the exhaust side. That way when it opens it draws in fresh air. The Egr will still function like it should and throw no codes

 

[GP98GTX]

Well if u want to delete it so it's not putting exhaust back into the intake use a block off plate. Block off the exhaust side. That way when it opens it draws in fresh air. The Egr will still function like it should and throw no codes

The 'up-tube' from the manifold, on this motor, is part of the EGR assembly's mounting (The intake manifold isn't threaded, it only has through holes).
I had originally thought to put a filter similar to the push-on style VC breathers but decided against it, in-case of some nosey SMOG tester. (I travel to CA regularly)

Leaving everything 'looking stock' was the goal and hiding a switch and two 22AWG wires was much easier.

 

[BillBoost37]

Sorry..I was trying to answer part of the question Keith posed to your thread.

As for being able to do it with a switch. I don't see how. The pcm will command the EGR to run various tests. If it doesn't get responses to pintle position etc etc it will throw codes. Also the PCM looks for a change in map readings when it commands the valve open.