Can you post some pics of the removal!!
Disable the EGR system the (mostly) Toyota way (1 Viewer)
- Thread starter Ebag333
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- Thread starter
- #122
Funny how much opinions can change over time- my own included
Anyway, I've gleaned the following from the above post:
1. it looks like Bear80 ('97 80) was using a 1k (0.25W or 0.5W rated would work) resistor without any problems
2. zipastro ('94 80) had his working for 2 years on a 1 OHM (not 1k) resistor, which is possibly further evidence that the OBD1 trucks are less sensitive to this mod
3. scoop ('97 80) did the 1k resistor mod and it apparently caused a "not ready" ECU condition (NOT a CEL) when it came to emissions testing, even after 1,000 miles
4. BrettinSanAntonio posted this info on expected resistance values of the temp sensor:
According to the FSM the ranges are:
122 (F) - 64K -97K Ohms
212 (F) - 11K - 16K Ohms
302 (F) - 2K - 4K Ohms
Does anyone (CDan?) know if a temp-sensor-like connector is available with open terminals to make it easier to insert a resistor in it? I'd rather not cut the temp sensor probe off to do this mod.
I'm still guessing that the OBD-II trucks are much more sensitive to this. Apparently they aren't that sensitive though as many people are running with out of spec resistors (1k resistors) and I ran with no resistor for nearly 1k miles (many of it freeway) without issue (and the ECU flagging green).
OBD-I and OBD-2 appear to have their connectors reversed.
Why? Don't ask me.
Here is my new resistor 4.7K ohms!! Not fancy, but gets the job done!! Still all tucked away like before!! I'll keep you posted!!
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looks good Darren....thats pretty much what I did except I stuck a piece of heatshrink in the middle.
Hope it works for you.
I haven't had a check engine light on mine since I did it.
Hope it works for you.
I haven't had a check engine light on mine since I did it.
Note that trapper92 has a '94 with OBD1, which may be less sensitive to this mod according to what we've seen so far...
Thanks again for the help!!
so if you have an obd 1 truck which resistor do you use, and across which terminals, in this thread ive only found ob2 stuff, ill go back and read some more, but if somebody would let me know it would be greatly appreciated.
Thanks again
Will
Thanks again
Will
try this thread!!
https://forum.ih8mud.com/80-series-tech/332126-94-code-71-egr-bypass-redneck-technique.html
hope it helps!!
https://forum.ih8mud.com/80-series-tech/332126-94-code-71-egr-bypass-redneck-technique.html
hope it helps!!
Have a 93 and heck I don't even have a sensor. Just a plug in the side of the EGR where the sensor would screw in.
That being said I'm assuming I could just plug the two lines to the tb and all would be well in the world?
What about the line from the EGR valve T fitting that run to the back of the manifold. Does it need to be capped?
And if this takes the EGR out of the loop is there really any need to remove the pipe and EGR? Seams like a lot of work for something that doesn't work anymore.
That being said I'm assuming I could just plug the two lines to the tb and all would be well in the world?
What about the line from the EGR valve T fitting that run to the back of the manifold. Does it need to be capped?
And if this takes the EGR out of the loop is there really any need to remove the pipe and EGR? Seams like a lot of work for something that doesn't work anymore.
You got it....the vacuum source for the system is the TB, unplug and cap and your good to go.
No sensor.....no check engine light to worry about.
That line that goes to the manifold goes to the VSV, just leave it...its simply a 'blow off' or on/off switch for the vacuum that would be going to the egr that is now nonexistent. (since you unplugged the source) ....get it.
Sure...leave everything in place if you want. I did.... as I still need mine to pass our emission testing every 2 years. I just hook it back up for the test.
alaskacruiser said:
Ebag333- I was just looking at this again, and as the temperature reading from the temp sensor goes higher, the resistance of the temp sensor goes lower. So if we simply short the terminals as we're doing, then are we not possibly producing an out-of-spec , abnormally high temperature reading to the ECU? And could this not explain the P0402 (excessive flow) CEL? Perhaps simply using a resistor in the 2-4K range will fix this on the ODB2 trucks. let us know, kup99, and also make sure to block those vac lines.
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about 50 Miles ..... lots of cycles, .... nothing yet!! still need to block the vac. lines though!!
I googled P0402 to find "EGR excessive flow at idle", so perhaps the ECU is looking for a certain resistance range from the temp. sensor during idle, and then a different range when cruising? Perhaps simply using a resistor in the 2-4K range will fix this on the OBD2 trucks, but to really figure this out, I think we need to ask: is it documented anywhere what temperate/resistance range the ECU is looking for from the temp. sensor under different conditions (idle, cruising, etc.)? Is this in the FSM? Anyone know where to find this info?
- Thread starter
- #134
That's exactly my thought.
My initial thought was that Mr. T coded in to the ECU an exception for basically 0 resistance (bypassed line), and that appears to be exactly how the OBD-I trucks work. It's trivial to do that, and that makes a lot of sense.
But obviously it isn't working in the OBD-II trucks, so it looks like it's back to the resistor method.
Since I got this idea from a club member who has his truck setup this way (and has for years), it must work. His is a '94 however, which means OBD-I.
- Thread starter
- #136
it's a '93 and came from the factory with the jumper: see the first post y'all.
and yup- seems OBD I ECU is the one for simple fooling; however a couple resistors is nothing compared to my last EGR fooler for an '07 Liberty CRD
Yeah.....lets see if Darren gets a light.
firetruck41- thanks for the info. I was about to say I already quoted this info in post #106 in this thread, but I noticed 2 things:
1. The values you posted are slightly different
2. Then I noticed they're not just slightly different, but VERY different because the values you list are in Ohms and not kilo-Ohms! I'm thinking this is a typo in the manual, but I need to know which are the correct values!
I believe the values I quoted from BrettinSanAntonio in #106 were from an OBD1 manual.
Here's a comparison (Brett's / firetruck's values):
122 (F) - 64K-97 KOhms / 69-89 Ohms
212 (F) - 11K-16 KOhms / 11-15 Ohms
302 (F) - 2K-4 KOhms / 2-4 Ohms
Can someone with an OBD1 EWD confirm Brett's values?
Also I think I should clarify my last post, because the data you posted (although very valuable!) isn't what I was asking for in my last post.
Let me restate for comment since this may not have been clear to others, either: I googled P0402 to find "EGR excessive flow at idle", so perhaps the ECU is looking for a certain resistance range from the temp. sensor during idle, and then a different range when cruising? Perhaps simply using a resistor in the 2-4K range will fix this on the OBD2 trucks, but to really figure this out, I think we need to ask:
Is it documented anywhere what temperate/resistance range the ECU is looking for from the temp. sensor under different conditions (idle, cruising, etc.)? Is this in the FSM? Anyone know where to find this info?
Thoughts, comments?
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