Autozone Scanners

Seriously though, just go to Autozone and get it scanned. there are a

> zillion things that set the light! >

I went to Autozone and had my 97 scanned. It said my EGR is bad. (My check engine light is also on.) My friend has a scanner as well, and it said the EGR is bad.

Is this enough to just go ahead and have the EGR replaced, or should I go to a shop and have the engine scanned by one of their scanners?

Don

Reply to
Donald H. Shelton
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Haynes manual has some tests you can do to determine whether it is the ERG valve or a sensor. Try that and replace what those tests indicate.

Reply to
Ratbert

The DPFE is a more common failure than the EGR valve. We would need to know what code was set to recommend a diagnostic procedure.

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

The code P0402--Excessive EGR Flow

Don

Reply to
Donald H. Shelton

Eight times out of ten, that one comes up as bad DPFE..... There is a real easy way to test the DPFE but it does require a scanner capable of displaying PIDs (parameter indication data). A digital multimeter can be used but there's too much chance of damaging the connector when back-probing.

DPFEs aren't terribly spendy.... since they are a know area of concern, I'd seriously consider slam dunking a sensor on, clearing codes and trying it. The usual precautions apply... check the hoses and electrical connections, use a vacuum guage (a real one, not the tip of your finger) to be sure that the EVRV isn't leaking. From the factory, the hoses would be silicon rubber - regular rubber will suffice as a temporary substitute if they need replacing and no suitable hose is available locally. When removing the hoses, work gently. Though the silicon rubber can withstand amazing amounts of heat, it can be mechanically damaged very easily.

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

Interesting. I work with digital controllers, and I know PID as meaning Proportional Integral Derivative, a method of calculating an output given an input. Are we referring to the same thing?

- mike

Reply to
mike w

No..... in the automotive sense, a PID would be a data stream reading. It may be something as simple as an on/off signal regarding an input or an output or it may be a little more complex such as a sensor voltage reading or even the same voltage reading converted to it's inferred value (throttle opening in percent or temperature seen by a sensor, for example).

When it comes to Ford, we are faced with a barrage of acronyms. Our two industries are faced with different terminology with the only commonality being the first letters of a particular item or function.

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

FWIW, I also got a scanner code for "Insufficient EGR", pointing to possibly bad DPFE. This is in our '96 Explorer (4L 6 cyl) a couple years ago.

I back-probed the DPFE, used a couple small nails (brads) by pushing them into the connector until they touched the metal tabs. I didn't have to pierce the insulation (although that's another way to do it). Used multimeter probes with the small alligator clips on the ends (instead of the touch probes). You can get these as Radio Slack. From there, it was easy to diagnose.

Bottom line, per the Haynes description, my DPFE was in fact bad. Replaced it and reset the computer with the scanner. Have not see the Check Engine light since.

Verified it really was the DPFE by drilling out the rivets and taking the thing apart. The flow sensor chambers were all gummed up with what looked like large grains of pepper, probably a half teaspoon of gunk in all. No wonder it wouldn't work (thus throwing off the EGR balance).

Backprobing should work fine.

Mike

Reply to
Mike Mayer

Done gently and carefully, backprobing is better any other method other than using a breakout box type harness (or even better, PID data). Straight pins such as those used in sewing work well. I recently suffered through a F150 that some well intentioned soul had pierced the wiring insulation in in many places without resealing the wiring..... I had green stuff that used to be wire all over the place...... after several hours of wasted time, we decided that a new harness was the only way to go. Now all that remains is to see if I get paid for my efforts or if we negotiate a deal because someone else "saved money".

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

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