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96 obs 2.2L, 180k miles ...getting 17.5 mpg city. CEL came on yesterday. Read code today... PO400 code

 

EGR system fault (would this cause the bad gas mileage?)

 

The ECM has detected too little flow on the EGR system

 

probable causes

 

blocked passage on the EGR system

failed EGR valve ($175 new!) :slobber:

EGR selonoid faulty

failed egr pressure sensor where applicable

failed egr position sensor where applicable

 

 

What do you guys think I should do next? I've been through this on another car I owned and started buying parts, installing them and hoping it solved the problem. I'd rather not do it that way again because it's random and expensive.

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I've been cursed with EGR problems on 2 vehicles now. Yes, that would cause the bad mileage!

 

First of all, check under the hood for all your vacuum lines going to/from the EGR itself. Maybe one came loose or cracked. Lines good and tight? Test the EGR to see if it moves. Suck on the hose going to the EGR from the vacuum switch. If the EGR moves, it's not clogged. No movement? Look through the hose. Hose clear? At that point, you could try cleaning the EGR itself. Don't use solvent!

 

If that doesn't fix your problem, that's when you test everything else (solenoid, etc.) until you've eliminated what it can't be.

 

Still have the $%@*^@$ code? You could try other suggestions (I'm sure other posters will have some) but if NY has a dollar limit on emissions repair for yearly license renewals, it might be time to bite the bullet and have a shop take a peek. Your fees to the shop should count towards the repair limit for a waiver.

 

If you believe it is your EGR valve, you could try finding one at a junkyard (do a vac test on it to see if it's OK) and popping it in before you spend money on a new OEM part. If it moves in the junker and the code still pops up, I'd consider it's not the EGR. You'd be out the cost of a gasket, but it's still cheaper than a new one if you're not sure it will fix it! In my area used EGRs don't cost a lot.

 

Remember to disconnect your battery after doing all the EGR work so the old codes are cleared - I know people will tell you 1 minute is plenty, but I've found that some cars need 10 minutes. Hate to see you fixing a 'problem' that isn't one any longer just because the old code is still stored.

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hehe there's a good article on endwrench.com about egr code issues, maybe there's a pic of the filter in there. It also says sometimes some of the low points in the metal tubes rust out....ok over to endwrench to see if there's a pic. wow putting that part #22663AA010 into google only turns up two hits, one a japanese site with the part # mentioned in some pic of a turbo engine of some sort.

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hehe there's a good article on endwrench.com about egr code issues, maybe there's a pic of the filter in there. It also says sometimes some of the low points in the metal tubes rust out....ok over to endwrench to see if there's a pic. wow putting that part #22663AA010 into google only turns up two hits, one a japanese site with the part # mentioned in some pic of a turbo engine of some sort.

 

I put the number in to google too and then got 1stsubaruparts but then couldn't find it on their site. weird.

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I'm not sure if this is the filter, but was the only thing that looked like it might be something like that, circled in red, is this it?

filter1c.jpg

 

Also I imagine these metal lines crossing under the throttle cable are the ones the endwrench article says they have seen plug up or rust out

egr96-2.jpg

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Okay guys shoot me for being old scool old fool.

 

Can he test the EGR control solenoid

like we could on the EA series engines?

(Resistance check of the coils for ~35 Ohms)

 

Do they fail with anywhere near

the regularity that the EA solenoids do?

 

 

 

 

If this is not relevent please dismiss it as

just some rambling from an aged fart.

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The ECU uses manifold pressure to monitor EGR flow, via the MAP (manifold absolute pressure) sensor.

 

When the EGR valve opens it causes a change is manifold pressure. If the ECU doesn't see enough change it will flag a code for EGR flow problem.

 

If this filter to the MAP sensor is restricted (doesn't take much), the manifold air pressure readings are not necessarily affected. But the slight change is pressure when the EGR valve opens is not detectable.

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Also.............

 

Yes, rust in the vacuum lines could cause the problem.

 

As native Montanan cars are rust free, that isn't a problem I see, so it is not the first thing to come to mind.

But should be checked if one lives in the rust belt.

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I removed that little filter today. I blew it out both ways with low pressure air and reinstalled. I probably ruined it doing that. I need to get an inspection stick ASAP so I don't have time to wait for a new one to arrive.

 

Removed the neg battery cable for 10 mins and started it up. CEL is out for now. At least I can get my sticker. :dead:

 

All the rubber vacuum hoses are the consistency of hard plastic. They don't appear to be leaking though .

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[...]Removed the neg battery cable for 10 mins and started it up. CEL is out for now. At least I can get my sticker. :dead:[...]
Fortunately for you, '96 Subarus have a problem with the OBD-II I/M readiness monitors resetting every time the key is turned off. Therefore, as long as the CEL is off and there are no pending codes, you might pass. For later model years, monitors not being ready is in itself a reason to fail inspection.
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i dont really understand... whats an IM readiness monitor? Are you saying that only the 96s dont hold codes?

 

If the cel light is off, I don't think they;d even bother plugging in the tester. If the cel is on they immediately fail you and charge you the fees anyway.

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Right on, many '96 soobs have been granted exemption from the inspection readiness monitors (I/M's) because they reset to 'not tested' or 'not ready' every time ingnition is turned off.

 

I checked my '96 legacy before just prior to NYS inspection, and many of the readiness I/M's were not ready or not tested, yet it passed no problem.

 

There is an article on endwrench about this issue; can look up if desired.

 

In NYS, as I suspect in many areas, the ODBII is connected to the test equipment, making it a little trickier to 'fake it out'.

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I'm not sure if this is the filter, but was the only thing that looked like it might be something like that, circled in red, is this it?

filter1c.jpg

 

Also I imagine these metal lines crossing under the throttle cable are the ones the endwrench article says they have seen plug up or rust out

egr96-2.jpg

 

 

Where is this located on a 99 OBW. I got the same code in my computer, but I don't see anything that looks like this under the hood.

Thanks.

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discostu is your MPG really bad now?

 

Mine went down to 15mpg city.

 

I blew out that filter, unplugged the battery to get rid of the CEL and filled the gas tank again. I hope the MPG is better next time I check it.

 

The CEL hasn't come back on in 50 miles of driving.

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