Trouble Code Shuffle----egr related

[StWeiler]

Guys, I"m in need of some wisdom.

1999 3.0 auto 4x4

Started off as running rough, stuttering, etc. CEL came on.
Codes Read: P0409 - Egr Valve & Code 1301 (I think)- missfire

So I swapped out the EGR valve and cleared the codes. No more than 15 miles later CEL comes back on. Now it is code P0401 and code P1301.

It's running like crap, and get HORRIBLE fuel mileage. Before I throw any more parts on it, I'd love some insight on what to look for? I've been told a multitude of things...EGR Flow Tube, IAC, MAF. I'm at a loss.

 

[Mazda]

This is the site to go to when someone has a EGR - DPFE- related problem.

http://easyautodiagnostics.com/ford_egr_test/ford_egr_valve_1.php

Read all the pages and go step by step and you will solve the problem.

Bryan

Also first check the hoses to the DPFE valve. Sometimes they will come off. Or get a hole or crack in them. I had this problem once. Put a few small hose clamps fixed the problem.

 

[adsm08]

Are you sure it's a P1301 and not a P0301? I can't find a code definition for 1301.

 

[RonD]

And just FYI.

The Pxxx codes are for narrowing down what to test, they rarely ID a bad part.
People often get frustrated by "computer controlled" engines because they feel lost or they read a code and replace a part and still get the code or another code.
The "code" is helpful but not specific.

In an older engine, rough running with poor mileage could be distributor, carb or EGR.
With newer engine and OBD(on board diagnostics) the CEL narrows it down for you, in this case EGR system, so way way easier to find and fix problems with this system.
You don't have to test ignition or fuel, just EGR system, very cool.

 

[StWeiler]

Well, replaced the dpfs and hoses. All was good for about 50 miles....and THEN the damn CEL came back.

Now I get P0402 and P1501. Aye carrumba. Burned a full tank of gas in 190 miles.

Sent from my Nexus 7 using Tapatalk 4

 

[RonD]

You need to use a Volt/OHM meter and test parts before replacing them.

You could have a mechanical issue so replacing valves and sensors is useless.
EGR flow comes thru a pipe from the exhaust manifold, it could be restricted or blocked, so mechanical issue, the computer only has one method to give you a "heads up" about this, the CEL and an EGR related code.

There is lots of info on "the net" about how to test Ford sensors, valves, and other devices, so no need to empty your wallet to find a loose bolt or blocked tube.

And just another FYI, the 50 mile thing, or the delay, is the computer testing the engine operating parameters, it has a routine(software) it follows before turning on the CEL again.
This delay is often handy in determining a fault as well, for example, if a sensor is not "talking back" to the computer, the computer might activate the CEL within a minute or two of starting, so bad wire or bad sensor "could" be the problem.
A delay can mean the computer is waiting for the engine to warm up and is then comparing O2 lean/rich numbers with other data from other sensors, once it determines there is an issue it would turn on CEL and set a code for "probable" area of the problem, not "for sure" area, just "probable" area.
The computer is a simple IF>THEN problem detector, the term "diagnostic" in OBD is a bit of an overstatement, lol.

 

[kimcrwbr1]

To check the egr with the engine running at an idle hook manifold vacuum to the egr so it fully opens and the engine should stall. If not there is a blockage from the egr to the exhaust port/s on the heads. Really common on an engine with bad valve guide seals they plug up with carbon buildup.
http://www.ebay.com/itm/1998-2002-F...Parts_Accessories&hash=item2c73fed779&vxp=mtr
Did you pull the tube and look for blockage?

 

[StWeiler]

It has now evolved into a P0174 (lean bank 2). I am going to assume this is vacuum related. Are there any common areas to begin the search? I don't have a vacuum leak down tester or anything like that. I was thinking I'd just use carb cleaner and spray around until I hear a subtle change in RPM's? Reasonable?

 

[kimcrwbr1]

Use the poor mans stethescope a length of vacuum tubing about two feet long. Put one end up to your ear and search around with the other. Be careful of moving parts did you replace the PCV valve. The closer to the leak the louder the hissing.

 

[kimcrwbr1]

Did you fiddle with the throttle butterfly stop? Bring the engine up to normal temp and open the throttle to about 2000 rpms and unplug the idle air control motor and let off the throttle and see what it does. That should fully close the IAC, If you still have a high idle adjust the throttle stop until it barely idles and quickly plug in the IAC it should then control the idle speed. Worth a try I will look up the proper way to adjust the throttle butterfly if it is my book.

 

[naford]

Here's a stupid test. Read the codes write them down, clear the codes, drive the truck until CEL comes on, read the codes, write them down, clear the codes, drive the truck until the CEL comes on, read the codes, and write them down. You could also read the code then drive the truck for longer periods and see if the codes change.The reason for this is to verify that the same codes are coming in every time without any work being done on the truck and sometimes the first sensor to throw a code is just the first sensor read. Some codes take longer drive times before they will report as a failure. I think EGR would be one of these codes. Just from the nature of what the EGR does. Correct me if I'm wrong but I don't think the EGR is open during idle but does open up at higher speeds. From what I've seen you had an EGR circuit "A" problem, that went to a speed sensor problem, and now gravitated lean condition on bank 2. One of two things are occurring. The first is that something is wonky causing the computer to miss read the sensors or every time you fix something you break something else. Because of the age it is easy to crack a hose and not know it. The lean condition on bank 2. Cause a wire to short or open. Speed sensor.

 

[StWeiler]

Would this vacuum line that has bypassed have anything to do with it? Anyone have a picture of how it is "supposed" to be routed, or to what?

<a href="http://s1143.photobucket.com/user/StWeiler/media/vacuum2_zpse1f04545.jpg.html" target="_blank"><img src="http://i1143.photobucket.com/albums/n629/StWeiler/vacuum2_zpse1f04545.jpg" border="0" alt=" photo vacuum2_zpse1f04545.jpg"/></a>

 

[StWeiler]

Anyone with a 3.0 willing to shoot a picture and upload so I can at least see where your vacuum line is routed? I can't seem to figure out where that stupid thing is supposed to be routed.

TIA

 

[StWeiler]

Here's a stupid test. Read the codes write them down, clear the codes, drive the truck until CEL comes on, read the codes, write them down, clear the codes, drive the truck until the CEL comes on, read the codes, and write them down. You could also read the code then drive the truck for longer periods and see if the codes change.The reason for this is to verify that the same codes are coming in every time without any work being done on the truck and sometimes the first sensor to throw a code is just the first sensor read. Some codes take longer drive times before they will report as a failure. I think EGR would be one of these codes. Just from the nature of what the EGR does. Correct me if I'm wrong but I don't think the EGR is open during idle but does open up at higher speeds. From what I've seen you had an EGR circuit "A" problem, that went to a speed sensor problem, and now gravitated lean condition on bank 2. One of two things are occurring. The first is that something is wonky causing the computer to miss read the sensors or every time you fix something you break something else. Because of the age it is easy to crack a hose and not know it. The lean condition on bank 2. Cause a wire to short or open. Speed sensor.

I performed this "dummy" test today.
Round 1 & 2: Codes thrown P0402/P0174
Rounds 3-5 : Only code P0402

I should note: It has a horrible surging up and down at start up. It eventually levels out but at every start up it surges up and down like mad.

 

[naford]

All motors surge it's just so slight you never notice. So a 402 code is excessive EGR gases. You've replaced the EGR and the DPFE. I'd go to the website that Mazda has on the first page and go through the procedures.