EGR issues

[bigmuskie]

Hello all, I have a 2001 Mazda B3000 3.0 V6, not sure if it matters, but it's a 5 spd. 2wd.

The issue; I have a check engine light on once again. I went to Autozone to have the code read and it came back (insufficient flow EGR) I replaced the EGR with a new one. Also, I disconnected the battery to clear the check engine light. All was fine, check engine light out, for about 53 miles till the light came back on. So I went back to Autozone to reread the code and it came back (insufficient flow EGR) again.

He had entered in the computer as to what could be causing the issue. It had stated a possible blockage in the metal tubing or the vacuum line itself.

Before I go tearing into this, I would like some feedback and/or suggestions from those who have first hand experience.

Thanks.

big

 

[BeaterMan]

its the DPPE feedback sensor. its a pretty common thing on these vehicles. if you follow the 2 vacuum hoses comming from the egr tube they will go up a sensor atop or next to the intake manifold and that will be you problem. its been a while so i cant tell ya how much it costs tho.

 

[ThreePointO]

It could very well be that a bad DPFE is causing your computer light to come on, but sometimes just disconnecting the battery won't clear the computer - before you do anything go back to Auto Zone and have them clear your computer with their scanner and see if that doesn't fix the problem.

 

[bikerboy]

but sometimes just disconnecting the battery won't clear the computer

If you disconnect the battery for any longer than 5 min it will clear your PCM memory and all its settings.

Here is a test for your DPFE sensor. Do this before replacing any more parts. A good diagnosis is almost always cheaper than throwing parts at it.

1. Start with checking the Differential Pressure Feedback EGR (DPFE) sensor voltage. This can be done on the scanner or at the DPFE sensor on the Brown/Light Green (BR/LG) wire. The voltage should be close to 1.0v Key On Engine Off (KOEO).
2. If the voltage is incorrect, verify that the Gray/Red (GR/RD) wire is a good ground and that the Brown/White (BR/WH) wire shows 5v. Also be sure the wires are good through the connector and that the connections are good between the pins in the harness connector and the pins of the DPFE sensor.
3. If the Key On Engine Off (KOEO) voltage is incorrect, but everything else looks OK, replace the DPFE sensor and retest.
4. If the voltage is OK, apply 8" vacuum to the "REF" port of the sensor (the smaller of the two ports) and the voltage should increase to at least 4v. If it does not, replace the sensor.

 

[bigmuskie]

Appreciate the help. Turns out it was the DPFE. I bought one from the local Autozone for 53.00. While replacing, I cleaned out the rubber lines with brake cleaner, hope that wasn't too harsh for the lines. Disconnected the battery for about 10 minutes or so, and so far, no CEL.

Thanks for the replies.

 

[RumpRanger98]

just curious, was this effecting how it ran at all?

 

[bigmuskie]

just curious, was this effecting how it ran at all?

Well I do have a hesitation issue, but replacing DPFE didn't clear that up, just gave a CEL, which is still off after a couple hundred miles.

big.