Help check engine light
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New User
Joined: Oct 2003
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Help check engine light
My check engine light is on. I am getting 3 codes, 1405,0411,0401. Does anyone know what is the likley causes and how to correct them.
0411 Secondary air injection system incorrect flow detected
0401 EGR flow insufficient detected
1405 DPFE sensor upstream hose off or plugged(Which hose is this)
thanks.
0411 Secondary air injection system incorrect flow detected
0401 EGR flow insufficient detected
1405 DPFE sensor upstream hose off or plugged(Which hose is this)
thanks.
Senior User
Joined: Dec 2003
Posts: 404
Likes: 0
From: Groton, CT
Looking at your engine from the front of the truck, just behind and to the right of the Throttle Body there is a small (2" x 3") box with an electrical plug and two vacuum hoses coming out the bottom. This is your DPFE (Differential Pressure Feedback EGR) sensor. The two hoses connect to the EGR pipe (two fittings) beneath and slightly behind your Throttle Body.
Check the hoses for deterioration, then check the pipe to make sure the nipples are not rotted or cracked. If the hoses are OK, then disconnect them at the pipe (make sure you note which one is which) and check to see if the nipples are clogged with carbon gunk.
If all of this checks out, then replace your DPFE. The DPFE senses EGR flow by measuring differential pressure in the EGR pipe between the two fittings. Your problem is somewhere in there.
If you go to my website and look at the photos of the TB upgrade, you can see the DPFE just to the right of the TB. It is mounted to the upper intake right below the throttle cable plate.
Hope this helps.
Check the hoses for deterioration, then check the pipe to make sure the nipples are not rotted or cracked. If the hoses are OK, then disconnect them at the pipe (make sure you note which one is which) and check to see if the nipples are clogged with carbon gunk.
If all of this checks out, then replace your DPFE. The DPFE senses EGR flow by measuring differential pressure in the EGR pipe between the two fittings. Your problem is somewhere in there.
If you go to my website and look at the photos of the TB upgrade, you can see the DPFE just to the right of the TB. It is mounted to the upper intake right below the throttle cable plate.
Hope this helps.
Last edited by BigRedBronc; Mar 13, 2004 at 07:06 AM.
Senior User
Joined: Dec 2003
Posts: 404
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From: Groton, CT
BTW, I just noticed your post says "no cats". That little mod could potentially give you all kinds of computer headaches on a '96, as the system is designed with three O2 sensors. The third sensor is between the cats and modifies your engine control systems based on what it expects to see coming out of the first cat with air injection.
Additionally, with the 5.0 if you open things up too much you will sacrifice low end torque in favor of high end horsepower. Low end torque is what you need to get these big monsters moving.
I have the factory Y cat, O2 sensor, and air fitting intact. Follow that with a 3" in 3" out racing cat, 3"in dual 2.5" out flowmaster 40 series, and twin pipes exiting behind passenger wheel.
Keeping the computer control systems intact to the maximum extent possible is vital in the later model MAF broncos. Get the computer confused, and you will sacrifice more power and driveability than your modifications will make.
Hope this helps.
Additionally, with the 5.0 if you open things up too much you will sacrifice low end torque in favor of high end horsepower. Low end torque is what you need to get these big monsters moving.
I have the factory Y cat, O2 sensor, and air fitting intact. Follow that with a 3" in 3" out racing cat, 3"in dual 2.5" out flowmaster 40 series, and twin pipes exiting behind passenger wheel.
Keeping the computer control systems intact to the maximum extent possible is vital in the later model MAF broncos. Get the computer confused, and you will sacrifice more power and driveability than your modifications will make.
Hope this helps.
