Check engine light, low EGR flow (1 Viewer)

[carolinatlc]

I'm out of town for work right now until Friday and my wife called and said the check engine light came on in the 80. It's a '97 with around 100k. I talked here thru plugging in the OBD II code reader and she said the code was a low EGR flow. I searched on the board and didn't see anything on this. Anyone have any ideas? My FSM is at home so I can't do much. Thanks for the help.
Brian

 

[landtoy80]

It is not a problem that you need to fix today and will not hurt motor. Just have her pull the EFI fuse and wait a min and put it in. This will reset the computer. You can fix the problem when you get home. Me and others have had many problem with the dam EGR.
We are hear to help.

 

[Cruiserdrew]

You need this part-90910-12079 from Toyota. It's the VSV that controls the EGR flow. It is located under the intake manifold, and I assume the heat in the area fries it over time. The book says to take the intake piping off, but with a looooong extension from below you don't need to. Mine did this at 75k, so you got good service out of yours.

 

[landtoy80]

It could be the EGR vacuum modulator as Toyota changed the mod from a small one to a FJ60 sized one. It could be dirty intake chamber,dirty temp sensor or bad VSV. Do testing before you spend lots of $$$. Clean up everything first then test and run for a while.
I would fix one part of the EGR system, it would work for a while then the light would return. Its a PITA but it can be fixed.

 

[Junk]

replace the VSV and be done with it.

 

[Beowulf]

Brian,

>> I searched on the board and didn't see anything on this. <<

There are a *lot* of posts here on ih8mud and the SOR archives. Search for P0401, that's the code for EGR Flow Insufficient. Expand your search to 365 days if necessary but there are definitely a lot of posts.

There are 4 replaceable components and the various electrical and vacuum connectors and the intake itself. The hardest piece to get to is the VSV for EGR so that's the last one any of us get around to testing.

Follow the tests in the FSM carefully. The problem can be with the EGR valve, the EGR modulator, the temp sensor, or the VSV.

Let us know what you find as we are always interested in resolved P0401's. It appears that O2 sensors and the various EGR codes are the primary reasons the MIL comes on in our OBD-II 80's.

-B-

 

[landtank]

Before jumping in and cleaning or replacing anything I'd start troubleshooting and try to either identify or at least rule out some of the components. That way you won't inadvertantly create another problem in an already faulty system. That's when the tail chasing starts .