EGR BOCK-OFF on California, and 94 DSMs

[94Talon2]

I'm currently doing an engine rebuild and it took 3 days in the hot tank for my intake mani to be clean. I want to keep it clean and I can only do this by blocking off the EGR. My car has a sensor in the EGR valve and if I block it off my check engine light comes on.

Is there any thing I can do? I was thinking about relocating the sensor in the intake mani somewhere.

 

[Kinetic Boost]

A way for you not getting a check engine light is to use a federal ecu from the years 92-93 not a 94 ecu becuase the 94 ecu and a CA ecu are the same and will trigger a CEL.

 

[ziggi's92tsi]

you can convert your ecu to fedral all you have to do is solder a resistor,
they have instructions on dsm.org go to the vfaq

 

[94Talon2]

I've been looking on vfaq and I can't find anything about converting it.

 

[Kinetic Boost]

Ahh I never heard that you could convert your ecu to a federal ecu. But if thats possible much easier and cheaper than buying a whole new ecu.

 

[Jebus[tuning]]

Originally posted by Kinetic Boost
Ahh I never heard that you could convert your ecu to a federal ecu. But if thats possible much easier and cheaper than buying a whole new ecu.

Well not really, you can pull a resistor off a CA ECU to make it a federal one...I don't remember which one exactly, but I think it's on the VFAQ.

 

[mitsuclipsegsx]

just use a plate to block it off

 

[STECARS]

Or you can just remove the CEL bulb from the cluster . and then replace it.

 

[ziggi's92tsi]

it's on the vfaq under short tips:

"Converting a 90-93 CA ECU to Federal ECU
All you need to do is solder a 1K resistor into the missing R129 position inside the ECU. If you look at some of TMO's pages, you will see the R129 and R130 resistors that the factory uses to program the ECU for different applications. With R129 installed, the ECU thinks it is one of the other 49 states and stops checking the EGR temp sensor"

 

[94Talon2]

Is this true for the canadian ecu as well?

thanks for the help guys

 

[94Talon2]

I just took out my ecu and I do have a resistor in (R129). To convert it v faq states I need to add a resistor. So what do I do?

 

[SpeedFreak03]

Sounds like you already have a federal ECU then...unless canadian ECUs are totally different? The R129 resistor thing was for cali ECUs only.

 

[tektic]

I'm using a 94 nt eprom ecu and it does have a resistor at r129. I'm using eb20 code. If I don't have my wideband hooked up I will throw a code 43 for egrt.

On the s3 forum it has been said a 10k resistor at the egrt pin will satisfy the check for the sensor. I had no luck with this. Maybe its a different size for dsm?

If anyone has done this successfully please pm me. I need to use my wideband in another car.

 

[serviceguy]

As mentioned before, later years 1Gs (94) were using an EGR temperature sensor regardless of the ECU configuration, the code was modified to ignore the FED/CAL configuration resistor (or at least for the EGR handling part). I bought a 94 eprom ecu and set it up for FED FWD but then to my surprise it still threw me an engine light for EGR.

If you have an eprom ecu you can replace the eprom with the E931 version (earlier and most frequently used as a starting point for ecu code modifications).

If your ecu is not eprom, besides finding an earlier ecu or an eprom one, you could probably get away modifying an EGR block off plate drilling a hole on the EGR inlet side, that way the exhaust gas would still get to the sensor but not make it to the plenum of the intake manifold. I've never seen this mentioned anywhere on the DSM forums I've been member of, and probably for a good reason since the temperature on that particular point of the manifold would probably get a lot higher than normal due to the lack of flow and that could trigger an engine light anyway, but it could be worth a try if none of the other possibilities is viable.

 

[bud09]

i was told that if you take off the intake manifold you can use a hex type slug screw to block off the port where the exhaust gas goes into the manifold, that way the passage is blocked but everything is still in use and won't throw the code.

 

[DSM1G90]

California DSM's in that era used a sensor on the EGR called an EGR Temp Sensor.

I had one of those Calif DSM's here in my current area and it did have the CEL code of a bad EGR Temp Sensor.

I found out that it was a sensor is sent voltage from the ECU where resistance readings tells the ECU on how the sensor is functioning. This was the clue on that a certain resistance value is what the ECU is looking for at a certain temperature range.

I found out the required resistance value that this sensor is sending to the ECU to keep things in a closed loop conditon.

Went to an electronics store and got a 1watt, 62K ohm resistor. One can go between 60K and 82K ohms and get the same results.

I went into the harness loom that is next to the intake plenum, opened it up and traced the wires to the offending sensor.

I cut one of the wires and placed this resistor in between where I made the cut with soldering the resistor inbetween the two ends.

I taped up the splice assembly and tucked it back into the loom where it can't be seen.

Got rid of the CEL since the ECU is now happy with the results and left the sensor intact to the EGR (which I later did a blockoff plate) and still connected with the wire connector to keep it looking stock as possible.

Did this trick over 10 yrs ago. Last I heard that the resistor is still working great and the vehicle passes sniff tests on a regular basis.

-DSM