Check Engine Light Code 71
Driver School Candidate
Joined: May 2016
Posts: 5
Likes: 1
From: Florida
How to check egr system
Check the egr valve by applying a vacuum to top part of egr valve the car must be warmed up and hot before you do this. Use a hand held pump with a gauge that shows u you are in a vaccuum.The car should stumble and stall out this will let you know the pinto inside is working. If it doesn't stall out the pinto is stuck and should be cleaned.
The next thing would be to check your vacuum modulator this has the letters p q and r on top of it remote the cap. I took mines out and blew through the bottom. You shouldn't be able to blow air through the bottom if you feel air going through bottom to top then the diaphragm inside the modulator is ripped or open. That's what happened to mine.
To check your vsv or vacuum switching valve remove it and attach alligator clip wires and apply 12 volts to it. If u hear a click then your solenoids are good. If not then its probably bad. The temp sensor should read 200 something at room temperature and to check it use a small pan of vegetable oil with a thermometer that can read up to 300 degrees farenheit. Attach alligator wires to the sensor and check for ohms. The higher the temperature the lower your ohm reading. At 300 degrees it should read 2 to 4 ohms. Hope this helps.....peace
The next thing would be to check your vacuum modulator this has the letters p q and r on top of it remote the cap. I took mines out and blew through the bottom. You shouldn't be able to blow air through the bottom if you feel air going through bottom to top then the diaphragm inside the modulator is ripped or open. That's what happened to mine.
To check your vsv or vacuum switching valve remove it and attach alligator clip wires and apply 12 volts to it. If u hear a click then your solenoids are good. If not then its probably bad. The temp sensor should read 200 something at room temperature and to check it use a small pan of vegetable oil with a thermometer that can read up to 300 degrees farenheit. Attach alligator wires to the sensor and check for ohms. The higher the temperature the lower your ohm reading. At 300 degrees it should read 2 to 4 ohms. Hope this helps.....peace
good post 92Ls1uzfe
Driver
Joined: Apr 2018
Posts: 68
Likes: 2
From: Texas
Giving Credit...
Check the egr valve by applying a vacuum to top part of egr valve the car must be warmed up and hot before you do this. Use a hand held pump with a gauge that shows u you are in a vaccuum.The car should stumble and stall out this will let you know the pinto inside is working. If it doesn't stall out the pinto is stuck and should be cleaned.
The next thing would be to check your vacuum modulator this has the letters p q and r on top of it remote the cap. I took mines out and blew through the bottom. You shouldn't be able to blow air through the bottom if you feel air going through bottom to top then the diaphragm inside the modulator is ripped or open. That's what happened to mine.
To check your vsv or vacuum switching valve remove it and attach alligator clip wires and apply 12 volts to it. If u hear a click then your solenoids are good. If not then its probably bad. The temp sensor should read 200 something at room temperature and to check it use a small pan of vegetable oil with a thermometer that can read up to 300 degrees farenheit. Attach alligator wires to the sensor and check for ohms. The higher the temperature the lower your ohm reading. At 300 degrees it should read 2 to 4 ohms. Hope this helps.....peace
The next thing would be to check your vacuum modulator this has the letters p q and r on top of it remote the cap. I took mines out and blew through the bottom. You shouldn't be able to blow air through the bottom if you feel air going through bottom to top then the diaphragm inside the modulator is ripped or open. That's what happened to mine.
To check your vsv or vacuum switching valve remove it and attach alligator clip wires and apply 12 volts to it. If u hear a click then your solenoids are good. If not then its probably bad. The temp sensor should read 200 something at room temperature and to check it use a small pan of vegetable oil with a thermometer that can read up to 300 degrees farenheit. Attach alligator wires to the sensor and check for ohms. The higher the temperature the lower your ohm reading. At 300 degrees it should read 2 to 4 ohms. Hope this helps.....peace
Sincerely...
Deaner
Driver School Candidate
Joined: May 2016
Posts: 5
Likes: 1
From: Florida
Code 71 EGR
I have a ‘92 Lexus LS400 with 146,000 miles on it now. It runs great. I maintain it and am generally pleased with it. I keep eyeing the LS430, but having a car that is paid off trumps an LS 430 everytime.
My CEL started coming on last week. It is intermittent. It comes on for 50 miles or so, then goes off for about the same distance. I pulled the code and it is Code 71, which is ‘EGR System.’ I have scanned this forum and found other people with Code 71 issues, but no clear repair results.
I removed the EGR valve and EGR vacuum modulator and inspected them for build up of any kind. I cleaned all EGR related parts with intake manifold cleaner, though they didn’t look dirty. I blew clean air through them. I replaced the little filter in the top of the EGR vacuum modulator. I checked for air leaks in the vacuum lines. Nothing. The CEL continues to come on and later go off randomly.
I see from this forum that the parts in the EGR system include the EGR valve, EGR Vacuum Modulator, VCV, VSV, and EGR Temp Sensor. I’ve read that the EGR valve never goes bad. I certainly don’t want to randomly change these parts one at a time. Based on what I’ve written, what would be the first part to replace?
My CEL started coming on last week. It is intermittent. It comes on for 50 miles or so, then goes off for about the same distance. I pulled the code and it is Code 71, which is ‘EGR System.’ I have scanned this forum and found other people with Code 71 issues, but no clear repair results.
I removed the EGR valve and EGR vacuum modulator and inspected them for build up of any kind. I cleaned all EGR related parts with intake manifold cleaner, though they didn’t look dirty. I blew clean air through them. I replaced the little filter in the top of the EGR vacuum modulator. I checked for air leaks in the vacuum lines. Nothing. The CEL continues to come on and later go off randomly.
I see from this forum that the parts in the EGR system include the EGR valve, EGR Vacuum Modulator, VCV, VSV, and EGR Temp Sensor. I’ve read that the EGR valve never goes bad. I certainly don’t want to randomly change these parts one at a time. Based on what I’ve written, what would be the first part to replace?
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