Hi guys,
my EGR function sensor went out on me, so I decided I'll just plug the thing up, and fake the ECU. I read the guide on istalling a relays on the wirig harness to the valve, but I don't really like the idea of a relay there due to the engine heat and also the possible visual inspection during the emissions test.

I came up with the following idea, and wanted to get some comments as to wether this should work or not.

To start with I would short circuit the wires going to the EGR function sensor. Then I would install a relay in the lines to the 4O and 3J terminals on the ECU.
I would wire the coil of the relay into the 4O line, and then insert the relay with the NC(normally closed) position into the 3J line.

If I read the FSM correctly this should fool the ECU into believing that the valve is perfectly happy. The ECU applies voltage to the solenoid on 4O to keep the EGR closed, and recieves a voltage on 3J when the EGR valve is open. Is this correct? So with this set up it should work like this:

4O+ == 3J-
4O- == 3J+


Now if they just would have had the function sensor signal the other way around all we'd need to do would be to bridge the 4O and 3J terminals....


Anyhow, let me know if this wouldn't work, or there is an even simpler solution.
Thanks.

 

Why are you going to so much trouble?

I haven't had my EGR in years and it still passes emissions and drives perfectly....

 

yup, same here...

 

Because the Check Engine Light annoys me, and they can fail me on emissions if the CEL is lit.

Apart from that, the EGR itself is disabled.

 

If you use a standard automotive relay such as this one - Auto-Relay, mount it to the fire wall, all your troubles will be gone.
I have been running this setup for quite some time now with no ill affects.

 

I know this thread is old, but I thought I could add to it regarding fooling the ECU from creating a check engine light for the EGR sensor.


You don't need to install the 12v relay and wiring under the hood with the engine heat. But under your hood I'd unplug the EGR Valve. Now the ECU won't read anymore sensor errors.

You can tap into the EGR sensor and solenoid wires where they come off the back of the ECU connectors.

The yellow connectors plug into the ECU.
The blue connectors hang behind the ECU.
White wires point to the EGR solenoid and sensor terminals.

EGR sensor terminals:


The EGR solenoid terminals:

Just splice into the wires that run out the back of these plug terminals. The solenoid wires would power the 12v relay. The sensor wires would go to the "normally closed" terminals.

 

Stock 49 state 93 ecu would fix the problem also.

 

Or upgrade to powerfc or Pettit ecu

 

I just did my egr bypass and found this post to be extremely helpful. I'd rather do this any day than try to pull all sorts of bits off (and mount bits) in the engine bay. A lot more discreet for those of us that have to run our cars under the smog noses

 

I have an M2 stage 2 federal (non-CA) ECU I was planning on putting up for sale soon. I was running with no EGR -- no CEL. LMK if interested.

 

I eliminated the EGR and faked out the sensor input to the stock ECU using this circuit, which worked fine. The circuit is small and fits next to the PCME (ECU).

 

I also used the work around fool the ecu relay mod. I did use a IC instead of the relay because I could hear the relay every time it operated...
https://www.rx7club.com/3rd-generati...rience-857507/