EGR code P0401 - correct resistor for "trick"?

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R

RL4x4

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1997 LC. Does anyone know for sure whether or not the ECU runs in "open loop" when the CEL is on?


At this point I am fed up and just want the annoying orange CEL gone! I have read conflicting reports as to which is the correct resistor to solder in.

Here is the info I have gathered from this forum.

"1k ohm, 1watt resistor."

"4.7k ohm resistor"

The FSM has the specs for the EGR temp sensor.

122 (F) - 64K -97K Ohms
212 (F) - 11K - 16K Ohms
302 (F) - 2K - 4K Ohms
“Based on the FSM values, I used a 3.9K, .5 watt”


Sooooo, what is the real answer??

Thanks :)
 
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I had the 401 for about 2 years before I got to take the manifold off and clean it up and replace a few goodies. The port between egr tube and intake plenum is more than likely plugged like mentioned in flanks post. That was my problem and still don's have a CEL.
 
Same here. Had P401. Replaced VSV and cleaned intake and so far no CEL.
 
I'm glad you asked RL, I have been looking too.

Can anyone answer with any amount of certainty for the hypothetical case of just taking the whole darn thing off (the EGR that is), is there a resistor to put in place that will get rid of the CEL? Reports are never very clear on searching through posts.
 
The through-port on the lower section of the intake manifold is clear and the upper port from the TB to the EGR is clear at both ends but I haven't removed the manifold to see if it is clogged in the middle.

I know some 'MUD members have had success with the resistor mod and I would really like to know which is the correct resistor for a '97.


Thanks
 
fixed 401 for now

Followed Flank's write-up. P401 defeated with pics. Replaced VSV and cleaned intake and so far no CEL and getting 50 more miles to the tank just in time for 4 dollar gas. :censor: for waiting 2 years to fixit.
 
Atoyot1031 said:
If you search "EGR resistor", you will find the following thread at the top of the list:
https://forum.ih8mud.com/80-series-tech/437888-egr-readiness-achieved-egr-removed.html

Search is your friend, and it's free!;)
Click to expand...

I searched no less than 20 threads for an exact and correct answer but I wasn't able to find one.

In the link you provided I wasn't able to find a direct answer.

A "warm" temp would be somewhere in the 2k ohm to 5k ohm range, and a "cold" temp would be in the 100k-200k range on the EGT temp sensor. How did I achieve this?

I put a 200k resistor in where the EGR temp sensor was, and I wired a 2k resistor in parallel with the 200k resistor. The 2k half of the circuit was wired to an automotive relay normally left open, and I used the ECU's VSV trigger to close the relay. When the ECU wants the EGR on, magically the resistance drops to a little over 2k.
Click to expand...
 
I am bumping this also. I have a 97 fzj-80 and I have read tons of differing opinions on which relay to use. Also, I have seen some posts (mentioned above) saying that I need to take out the glove box and speaker housing, and others that say it's just a 5 min fix and I only need to solder the resistor on the two wires that are behind the oil filter. My EGR is working, however I have headers installed so the headers don't route anything back to the EGR valve. I want to get the best performance possible with this setup, and also clear the check engine light so I can pass emissions. I just need some clarification on which resistor to use. And I am assuming that using the correct size resistor on the wiring harness behind the oil filter is all I need to do...?
 
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