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Topic: Cleaning that EGR

in Forum: C4 Fuel, Emission Control, and Exhaust Systems

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Cleaning that EGR (1/2)
 3/8/23 4:30pm
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Ocean Park, WA - USA

2001 Coupe, 1988 35th Anniversary Coupe currently used to own 1987 Coupe and 1998 Coupe

Joined: 9/30/2016
Posts: 52

I have been busy with winter life and that HVAC class, but now have regained some control.  Now it's time to conquer that dirty EGR issue.  The 33 codes have been showing up since I picked the car up Nov. 5 in Charlotte.  They cause the car to suffer hard starting issues sometimes, other times it fires right up, but I am only getting 24 mpg.  I have begun -- for now you can see first photo  - the connecting tube between the throttle body and the mass airflow sensor has been removed.  This MIGHT NOT fit when I install the BBR throttle body later.  The fit will be close.  For now, though, the issue with the EGR has caused a light puddling of fuel in the folds of the hose.  I hope I remedy that with the rotor-rooter thing.  Next, I am detailing the fasteners I will have to remove -- thankfully, they are a size I have -- looks like Torx 40.  And they are not hugely tight.  What I am going to do is remove the upper plenum (gee -- good opportunity to clean it up) and the passenger side intake tubes, to gain access to the EGR, then reinstall all of this stuff.  I will replace the rubber coolant hose to the throttle body during this, because it's often forgotten and a potential leak source and I don't know its history.  I didn't get the support from class with the rotor rooter thing, but got specific info from the instructor that I am not going to shove some kind of long brush deep where I don't see the results -- only clean up the EGR passage that a 2" or so intrusion will reach, vacuuming the whole time to avoid knocking too much debris into the intake valve areas.


 Second photo shows the black button-like 40 Torx bolts I need to remove so I can pry the intake tubes loose.

 Third photo shows the EGR

Just to the right of center in the third photo is the prize -- the EGR I will remove and clean up.  Hopefully that will resolve the 33 Code and bring on better performance.  You can reference its positon to the fuel rail valve.  Back to the garage!

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Re: Cleaning that EGR (2/2)
 3/8/23 9:58pm
Adams' Apple
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Duncanville, TX - USA

1985 Coupe-L98/Auto,Bright Red/Carmine. 1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.

Joined: 3/18/2009
Posts: 2205

Not sure how a problem with the EGR system could cause fuel to make it's way upstream into the intake air tube, but....in case you do not know, there are two "hidden" bolts that go in from the back side of the runner(s) you have to remove/loosen to get the plenum loose from the intake runner(s), or the runners off the intake base. You'll need a loooong #40 torx bit to get to either of them. If only removing the runners on one side, it is just the one bolt for that side. Good luck! 👍


Joel Adams  
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