Beno can you show me using this?
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EGR Problem??? (1 Viewer)
- Thread starter landtoy80
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Sorry for the delay...I'm terribly busy on my end.
Hope these pics are clear.
Hope these pics are clear.
Please excuse my ignorance, but does having a constant P402 or P401 due to having removed the EGR system do anything to the engines fuel efficiency?
I know that when I had a code for a bad O2 sensor I got terrible fuel mileage. Does the EGR system relay any info to the computer that effects air/fuel ratio like the O2 sensor system?
If not, I can see myself removing my EGR system if I ever get the dreaded code in a couple of years after I move back to Northern Idaho, the land of no emission laws.
I know that when I had a code for a bad O2 sensor I got terrible fuel mileage. Does the EGR system relay any info to the computer that effects air/fuel ratio like the O2 sensor system?
If not, I can see myself removing my EGR system if I ever get the dreaded code in a couple of years after I move back to Northern Idaho, the land of no emission laws.
Excellent question....maybe someone will chime in for this.
None that I am aware of. I have had it this way for almost a year now.
Many mini-truck guys have taken EGR valves off for a long time with no ill effects.
Read Robbie Antonson's answer to a question regarding EGR valves from the last TT issue. He makes pretty clear what the EGR valve does.
You can easily dupe the computer into thinking the EGR valve is still there by putting a resistor with the correct current into the EGR temp. sensor position and "tell" the computer the correct electrical value. The FSM has a test for this and basically you would mimic that test to show a positive value with the correct current running from the sensor to the ECU.
By getting rid of the EGR valve you are getting rid of almost 1000 degrees of heat at the back of the block. I don't mind that one bit.
-o-
Many mini-truck guys have taken EGR valves off for a long time with no ill effects.
Read Robbie Antonson's answer to a question regarding EGR valves from the last TT issue. He makes pretty clear what the EGR valve does.
You can easily dupe the computer into thinking the EGR valve is still there by putting a resistor with the correct current into the EGR temp. sensor position and "tell" the computer the correct electrical value. The FSM has a test for this and basically you would mimic that test to show a positive value with the correct current running from the sensor to the ECU.
By getting rid of the EGR valve you are getting rid of almost 1000 degrees of heat at the back of the block. I don't mind that one bit.
-o-
Thanks beno...my egr will be making a quick exit now.
That sounds great, I wouldn't mind losing that heat either. Perhaps that might have something to do with the HG warpage around cyl #6 that so many people have found.
Have you tricked your computer yet?
This makes me want to get my truck registered at my
's parents address just outside Coeur d' Alene, ID ASAP. I'd rip that system off in a heart beat even though I have not had any problems with it so far. (Knock on fake plastic LX wood trim)So do you guys not have emission regulations down there in NM?
Just curious, but any idea if this mod is Shamen approved?
Again, please realize that this is illegal in some jurisdictions.
I will not be held accountable for anyone else's actions. I'm merely showing what I did, nothing more, nothing less.
Thanks.
-onur
My LX started throwing the 401 code a couple weeks back every 20-25 miles or so. Clearing the code was starting to irritate me so I took the plunge today and started checking all the EGR components. The EGR valve, modulator, temp sensor and all hoses were fine. The port behind the throttle body where the exhaust gases flow was completely plugged w/ black soot. Cleaned it up, slapped everything back together including a new gas pedal cable and went on a 30 mile test drive. Woo hoo, no more check engine light.
I'd like to eventually get rid of the system like above on both Cruisers some time down the road. For now I'm just happy I don't have to keep clearing the code. I got rid of the EGR system on my '86 and haven't had any probs yet.
I'd like to eventually get rid of the system like above on both Cruisers some time down the road. For now I'm just happy I don't have to keep clearing the code. I got rid of the EGR system on my '86 and haven't had any probs yet.
Actually, Beno is incorrect. Tampering with the emissions system is illegal in ALL jurisdictions in the USA.
http://autos.yahoo.com/maintain/repairqa/exhaust_muffler/ques081_0.html
http://www.epa.gov/compliance/resources/policies/civil/caa/mobile/tamperpenpol.pdf
Revisions to the Clean Air Act in 1990 further broadened the definition of emissions tampering to include virtually ANY type of engine or exhaust system modification that alters what comes out the tailpipe. That means any nonstock aftermarket part that is installed on your engine must be EPA-approved and emissions legal.
Before the law was revised in 1990, it was only illegal for professional mechanics to remove or disconnect emission control devices. There was nothing to prevent a motorist from tampering with their own vehicles. That loophole has since been plugged.
Yes, we have emission regs in NM. Beno lives in a county that does not test for emissions... yet. In my county, they test me randomly and they test every newly registered vehicle. The employees that work on some federal property are required to have emissions testing if they bring the vehicle on government property.
Is it illegal? Yes. The fine can be as high as $2,500. Will you be caught? Probably not. Would you be fined if you were caught? Probably not. The EPA has bigger fish to fry but that does not make tampering with the emissions system legal in the US.
-B-
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That sounds great, I wouldn't mind losing that heat either. Perhaps that might have something to do with the HG warpage around cyl #6 that so many people have found.
Have you tricked your computer yet?
This makes me want to get my truck registered at my
So do you guys not have emission regulations down there in NM?
Just curious, but any idea if this mod is Shamen approved?
I have not tricked the computer yet. I have been toying with some different avenues in terms of dealing with the ECU and a desmogged vehicle.
One was sourcing a ECU from a non-US 1FZ truck, but that has its own problems inherent in a different market vehicle. Completely different set of operating standards and variations on ECU management...not the least that most non-US 1FZ's are mated to manual trannys.
But tricking the ECU is the next step...down the line here.
I live in a non-emission county in the ABQ area.
And, no, this mod is not Shaman approved. Then again, it's my POS not his.
Just so ya know, it is $2,500 per incident. The EVAP system that you removed is 1 incident. The EGR system is another. The CATs are a 3rd, and if you trick or replace the ECU, then that will be a 4th incident.
They may not be interested in going after you for $2,500 but $10,000 makes it more lucrative.
(.... wondering what my cut would be as a whistle blower....)
-B-
Illegal? I'm gonna pretend I never heard that. Alabama's atleast 20 years behind everybody else so I still have awhile before I will be concerned.
I'm gonna pretend I never heard that. Alabama's atleast 20 years behind everybody else so I still have awhile before I will be concerned.CEL cleared!
just wanted to shout out my appreciation for this site - I am a newbie with virtually no mechanical intuition at all and followed this thread to clear the P0401 code (it was the modulator) from the beginning steps on this thread...on my LX450 (no lockers unfortunately) i just bought...this site is one of my favorites already. Hopefully I can do all the dummy work from this site - thanks again!
just wanted to shout out my appreciation for this site - I am a newbie with virtually no mechanical intuition at all and followed this thread to clear the P0401 code (it was the modulator) from the beginning steps on this thread...on my LX450 (no lockers unfortunately) i just bought...this site is one of my favorites already. Hopefully I can do all the dummy work from this site - thanks again!
- Thread starter
- #36
I have updated added some pics to the first post is this thread and here too of the EGR system.
Top left VSV. Top Right carbon in the Modulator. My thought is when carbon get in the Modulator it also passes into the rest of the EGR system and plugs up the VSV and or hoses. When a chunk of carbon plugs up the VSV it causes a problem but the carbon might pass (like a kidney stone) making it hard to diagnose the problem.
Bottom is carbon buildup.
Top left VSV. Top Right carbon in the Modulator. My thought is when carbon get in the Modulator it also passes into the rest of the EGR system and plugs up the VSV and or hoses. When a chunk of carbon plugs up the VSV it causes a problem but the carbon might pass (like a kidney stone) making it hard to diagnose the problem.
Bottom is carbon buildup.
402 Occasionaly
I used to have the 401, I replaced the modulator like many others and it went away. That was about a year ago. I did it when I replaced my head gasket.
I also replaced all hoses in the vaccum system, bath washed all parts of manifold, etc., essentailly "rebuilt" the top half.
Curretnly, if I don't let the engine warm up for a couple of minutes (literally about 2 minutes) before starting to drive, it will throw a 402.
I know this is excessive flow. I have read many threads here, but don't really have a lead to why it might be doing this or where to look on the truck.
Thoughts?
I used to have the 401, I replaced the modulator like many others and it went away. That was about a year ago. I did it when I replaced my head gasket.
I also replaced all hoses in the vaccum system, bath washed all parts of manifold, etc., essentailly "rebuilt" the top half.
Curretnly, if I don't let the engine warm up for a couple of minutes (literally about 2 minutes) before starting to drive, it will throw a 402.
I know this is excessive flow. I have read many threads here, but don't really have a lead to why it might be doing this or where to look on the truck.
Thoughts?
My truck is throwing the 402 code, which I am wondering is being caused by the EGR valve being stuck or the modulator falsely commanding the EGR valve all of the time, or even a vacuum leak. The hoses seemed loose on their connections, but looked like they were in good condition. I am planning on looking closer into this problem this weekend, when I have more light and a bit of heat.
I got the 71 blues. I will commence checking for clogged EGR hoses since it's the quickest and easiest to start with. I replaced the EGR modulator a few years ago, but it was replaced with a green top. I'll check for carbon build up on that one too. Boo!
yesterday I was greeted with a rough+low idle and CEL. took me 24 hrs to find the thread that had the jumper technique and the diag codes ( https://forum.ih8mud.com/80-series-...es-realtime-help-appreciated.html#post4739334 ) and it led me to EGR ( check engine light code 71 on a '93 )
today, idle is normal, hadn't yet cleared the CEL, will try the EGR fixes noted above, wondering if it "passed a carbon stone" as theorized above.
today, idle is normal, hadn't yet cleared the CEL, will try the EGR fixes noted above, wondering if it "passed a carbon stone" as theorized above.
