Code 332......Can't find all my specific questions answered via searching

[roswell998]

Question..........When getting KOER 332 code with no other codes, can this cause engine to run rough and gas mileage to go in the toilet around town (about 10mpg) but mileage is pretty good on highway?

PLEASE READ DETAILS BELOW BEFORE POSTING.......

1. Allen screw removed and passage and nostrils were spotlessly cleaned then allen screw replaced a couple thousand miles ago.

2. New DPFE has only about 5-10K miles on it.

3. I just bought a new Actron 9190 code scanner since it will test all of my cars including both OBD I and OBD II. FYI, I got it on eBay for $260 shipped. So.......I'm running scans and studying them in addition to the KOEO and KOER tests.

4. I tried to run the cylinder balance test, but it stops short with an error message that test cannot be run until EGR flow problem is resolved.

5. I'm trying to figure where to start. Could the low mileage DPFE have failed this soon? Could the EGR valve be defective which appears to be a rare failure? CATS are original, but I can't find any evidence of them being stopped up. What's a good check for that and would clogged CATS throw a Code332?

Your help will be appreciated!

 

[SolidState]

I doubt it is your cats. If the cats weren't flowing correctly, there would likely be GREATER EGR flow.

I am guessing that the tube or the valve is not flowing.

FWIW, I have heard of the new aftermarket Wells DPFEs failing in short order. The Ford ones are expensive, but they tend to last a while. If you can find one.

 

[naval-avi8or]

Plugged intake nostrils. Just remove the throttle body (can be done thru the TB plate) and clean the carbon build up plugging the EGR return ports. It is the lower two round holes in the intake just after the TB.

 

[roswell998]

Plugged intake nostrils. Just remove the throttle body (can be done thru the TB plate) and clean the carbon build up plugging the EGR return ports. It is the lower two round holes in the intake just after the TB.

Allen screw removed and passage and nostrils were spotlessly cleaned then allen screw replaced a couple thousand miles ago.

They are still wide open. Actually done probably only 500 miles ago.

 

[naval-avi8or]

The venturi in the EGR tube can also get restricted by carbon. Thus not allowing the DFPE to have any input and refrence air.

Before that have you manually pulled vac on the egr valve. It should nearly **** the engine if the valve opens. Are the vac lines to and from the intake, DPFE and EGR valve cracked or broken.

 

[roswell998]

The venturi in the EGR tube can also get restricted by carbon. Thus not allowing the DFPE to have any input and refrence air.

Before that have you manually pulled vac on the egr valve. It should nearly **** the engine if the valve opens. Are the vac lines to and from the intake, DPFE and EGR valve cracked or broken.

Just pulled vac on the egr valve and the engine ran rougher but was nowhere near dying. Also, vac lines are intact.

How tough is it to clean the venturi in the EGR tube?

 

[SHOZ123]

The fact the EGR is NOT working will not cause the fuel mileage to drop. The code points to vacuum problems if all else is good. Maybe a bad hose going to the EGR vacuum solenoid?

 

[roswell998]

The fact the EGR is NOT working will not cause the fuel mileage to drop. The code points to vacuum problems if all else is good. Maybe a bad hose going to the EGR vacuum solenoid?

Checked all vacuum lines and they are ok. Also the EGR valve was vacuum tested and it is ok as well.

HOWEVER, I pulled the line off the intake manifold going to the EVR (EGR vacuum solenoid) and attached a hand vacuum pump. It will not hold vacuum. The air appears to be entering within the EVR so I got a new one and tested it. The same thing happens.

Has or can anyone do the same test? It's really simple to do. Pull the vacuum line going to the EVR (it's red plastic with a black rubber adapter on my car) which is near the DPFE on the intake manifold and attach a hand vacuum pump and see it it holds a vacuum.

Thanks for your help!

 

[roswell998]

Couple of assumptions that may answer my last question.

I think I figured out the answer to my last question.

I took the little cap off of the EGR vacuum solenoid and there is a small foam air filter in there. It appears that Ford's design calls for a small amount of air to bleed through there during idle into the intake manifold. But when driving the solenoid "closes" and blocks the flow of outside air through the little filter and redirects the vacuum to the EGR valve. Frankly this is an assumption on my part since I can't find any documentation describing the operation in that detail. However, it does make sense since the amount of air entering the intake during idle through this path is insignificant and additional air must be provided through the IAC valve to maintain significant idle speed.

 

[naval-avi8or]

Poor milage may could be a totally different issue (i.e. O2's). Have you tried clearing the 332 and then it re appeared.

The way I cLean the tube is by removing it and soak it in some berryman's. You can also use butterfly brushes or pipe cleaning brushes just be carefull. As I said in my last post it is a small venturi and if you go forcing or get rough poking things thru it you might damage it. What I mean by the venturi is the two small sensor tubes that enter the main tube actually protrude into the main tube and so that one senses static air and one air pressure just like a Pitiot tube and static port on an airplane (if your familure).

 

[SHOZ123]

I would think the small foam filter is how the solenoid bleeds off vacuum. Otherwise once the vacuum solenoid is active the EGR valve would be pulled open and stay that way.

 

[roswell998]

Hopefully out of the woods!

I would think the small foam filter is how the solenoid bleeds off vacuum. Otherwise once the vacuum solenoid is active the EGR valve would be pulled open and stay that way.

Agreed, but again when the solenoid is not active, it also leaves the vacuum line from the intake manifold open to external airflow through the small foam filter. Since the air is filtered, no harm is done and also the flow rate into the intake is a very small percentage of the total required (which is supplied by the IAC valve).

I replaced the DPFE with the Motorcraft replacement kit and it appears that solved my the problem. About a year ago the code 332 was being thrown along with a CEL. The DPFE was replaced with a Wells from Autozone and the code/CEL went away. However, the car still ran rough with gas mileage in toilet (abt 10mpg) but I assumed it was something other than the DPFE.

It appears that the Wells DPFE was defective from the start but was still within range hence no CEL or code 332. It would send the PCM incorrect signals that EGR flow existed but was low. The PCM would call for more flow which actually resulted in excessive flow. As time went by the Wells DPFE signal got worse and worse until the EGR control vacuum limit was nearly reached. The code 332 was then thrown even though the actual flow rate was excessive causing surging and poor mileage. I could see from scans at 50mph (Actron9190) that the EVR (EGR vacuum control valve) % would climb upward from about 30% to 90% and then stay there. The CEL would rarely come on but the scanner gave a 332 code every time on KOER tests. After replacing the DPFE the scans show a EVR range of between 30-50% at 50mph.

So.........bottom line is that a code 332 indicating insufficient EGR flow was being thrown when in reality the flow was excessive.

The car is running smooth as silk right now. :woohoo: However, the final conclusion will depend on the next couple of tanks worth of mileage. I'll post in a couple of weeks with a mileage update.

 

[projectSHO89]

So.........bottom line is that a code 332 indicating insufficient EGR flow was being thrown when in reality the flow was excessive.

Put another way, the MEASURED VALUE from the DPFE sensor was showing much lower than the actual flow Therefore, flow was increased trying to get the MEASURED VALUE up into proper range.

AutoZone parts strike again...

Steve

 

[roswell998]

Copy of spreadsheet created from Actron CP9190 scan

The following is a copy of an Excel spreadsheet which imports the data stored in the Actron CP9190 scanner in Datastream mode. Note that the EVR value runs about 40-50 when cruising at 60mph and drops to zero (as it should) under WOT or under closed throttle conditions. The EVR was pegged at 90 before the DPFE was replaced when cruising, so much more EGR was flowing than desired even though the code 332 indicated insufficient flow.

I will still post gas mileage results in a couple of weeks, but I expect it to be back to normal since the car is now running as smooth as silk!

Thanks for everyone's replies :thankyou:


View attachment 214

 

[roswell998]

Gas Mileage Update as promised + comments

LOOKING GOOD!

14.8 mpg.....
all intown with quite a bit of time at idle & WOT while testing with scanner.

22.3 mpg.....
combination of freeway, intown plus some idle & WOT while testing with scanner.

COMMENTS:
It is easy to assume that a 332 code means insufficient EGR flow in all cases but that is not necessarily true. It could mean that a well tuned system with no EGR restrictions (such as plugged nostrils) has a bad DPFE which is not a hard failure but basically one that is out of calibration and hence the PCM throws an erroneous 332 code.

If all else is perfect with no codes except a 332 code plus surging and gas mileage in the toilet, it just might be a bad DPFE as described above.



Again, many thanks for all of you forum members that have responded to my various posts over the past few months while fighting through this problem.
:thankyou: