Need help fast....
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Need help fast....
I've been fighting a losing battle to pass emissions recently and 'm running out of time, my 98 ranger 4 cylinder is throwing the P0401 Low EGR Flow code. I have replaced the EGR valve, the DPFE sensor, and spent hours with throttle body cleaner and a coat hanger trying to clean the flow tube running from the exhaust to the EGR valve. I'm running out of things to do, my only remaining ideas would be to replace the vacuum solenoid or the flow tube. Any ideas?
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Joined: Jan 2004
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From: SW Va
The EVR, it's vacuum lines & electrical connections probably belong on your suspect list for a P0401 code.
To do a quick function test on it, pull it's vacuum line connection at the EGR valve & do a blow back test. You should have resistance to the blow back, if not the EVR valve or the vacuum line back to it is likely leaking & that'll cause a weak vacuum control signal to the EGR valve & it won't properly open & can cause a P0401 code.
Also if the EVR's electrical connection is bad, it's operating electrical signal from the computer could be corrupt & cause it to not function right.
So if the blow back check seems ok, check it's electrical connector for corrosion, loose pins or sockets, damaged wiring & B+ operating voltage at KOEO.
Let us know what you find.
To do a quick function test on it, pull it's vacuum line connection at the EGR valve & do a blow back test. You should have resistance to the blow back, if not the EVR valve or the vacuum line back to it is likely leaking & that'll cause a weak vacuum control signal to the EGR valve & it won't properly open & can cause a P0401 code.
Also if the EVR's electrical connection is bad, it's operating electrical signal from the computer could be corrupt & cause it to not function right.
So if the blow back check seems ok, check it's electrical connector for corrosion, loose pins or sockets, damaged wiring & B+ operating voltage at KOEO.
Let us know what you find.
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