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EGR Tube Clean Out, Finally!!!!!

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#82 ·
Great Post! I am going to be cleaning the pipe today! So, I will be back with some pictures here in the afternoon.:cool:
 
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#85 ·
I am having the similar problem in disconnecting the EGR tube from the EGR valve.

The big brown nut has been loosened, but the tube stuck on the EGR valve despite I am trying hard to pull it out. Any other methods to remove the tube?


matthewquigley43 said:
The EGR pipe install photo shows where I removed some vacuum hoses that were in the way. You can see the EGR pipe with nut loose and pipe pulled free from that end. My first attempts to pull the nut end loose from the EGR valve were unsuccessful- even with WD40 and tapping with small hammer and pulling up hard.

I made a rope loop around the pipe close to the nut, and ran a pry bar thru the rope loop, put end of pry bar on metal tab that supports back of coolant tank(tank had been moved out of way previously), put strong upward pressure on pry bar, tapped pipe with hammer, and it popped loose. Yours may be easier to get loose.
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#87 ·
Hi all, I have cleaned the tube and keep getting the code for the mass air flow sensor. I replaced the maf sensor and am still having issues with idle and CEL still on. I am thinking I have a vacuum leak but am having a tough time finding it. I have cleaned the EGR tube to fix the original issue. The code that is set currently is for the MAS. A poster several post ago mentioned a key hole?? Not sure what they are talking about. thanks for the help!
 
#88 ·
PW2037FXR said:
Hi all, I have cleaned the tube and keep getting the code for the mass air flow sensor. I replaced the maf sensor and am still having issues with idle and CEL still on. I am thinking I have a vacuum leak but am having a tough time finding it. I have cleaned the EGR tube to fix the original issue. The code that is set currently is for the MAS. A poster several post ago mentioned a key hole?? Not sure what they are talking about. thanks for the help!
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You aren't telling anything. You must at least tell us what the code numbers are and what type of scanner you are using.
 
#89 ·
Thanks for your prompt reply!

I have done the EGR tube and EGR valve removal before I read your reply in alternative way.

Instead, I pull put the EGR valve first (thanks that the EGR tube is flexible), then I use the 22mm open wrench to loosen the nut (marked in red) and use the 24mm open wrench to clamp on the neck (marked in blue) to counter hold. Once the nut is loosen, then I rotate the EGR valve so I can get rid of it.

43sqd said:
The sealing ring/ferrule is keeping you from removing the pipe. Simply tap upwards on the pipe.
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#90 ·
43sqd, sorry for the lack of information. i was out of town and have been fighting this issue for a few weeks and trying to get passed emissions without taking it to the shop. I started with failing emissions and the code that was set was the P0400. I removed and cleaned the EGR tube (with help from this forum). I reinstalled everything and drove the car for several days hoping the CEL would reset. It did not after 3 days of driving. I used the scanner at Advance (i believe it was an Actron) and the codes it gave me were P0173, P0303,P0304,P0170. I was remembered the P0173 was for the MAF sensor and i thought maybe i had damaged the one installed during the removal and re installation while cleaning the EGR Tube so i replaced the MAF sensor. Drove the car for several days and the CEL still did not reset. At that point i tried disconnecting the negative battery terminal for 5 minutes to reset the codes manually. When i started the car again, it would barely run at first and then got slightly better once driven for a while. After returning from out of town today, i went back to Advance to see if the codes had changed and they had not. I cleared the codes this time with the scanner and the car seems to be running better now but i will see if the codes get reset in a few days of driving. I am not sure if it the results are the same clearing the codes with the scanner or clearing them by disconnecting the battery. I apologize for the long winded reply but wanted to give as accurate information as possible. I certainly appreciate the forum and all those that post on it and certainly do not want to abuse the help!!!! HAPPY NEW YEAR TO ALL!!!
 
#91 ·
Your above post is a classical example of not providing enough and/or the proper information.

1. What was the original code or codes that were set?

2. Was the EGR tube clogged?

3. Did you have a rough running eng. before you cleaned the EGR?

4. What brand/make MAF did you install?

5. Is the CEL presently on?


Codes P0170 and 173 does not automatically mean that the MAF is at fault. 95% of these codes are set because of vacuum leaks which causes the eng. to run lean. Running lean means that there is not enough fuel or too much air in the mixture formation.

If you did not have a rough running eng. before you removed the EGR pipe, then you forgot to connect or broke a vacuum hose or when you removed the air intake tube, you broke the lower locking tab which now enables unwanted air into the mixture.

Replacing MAF's have only made Robert Bosch richer than he already is and the misconception of codes P0170 and 173 are caused by a faulty MAF, only rivals the belief that Santa Claus actually exists.

If code P0400 returns you must replace the EGR valve.
 

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#92 ·
Jim, is there a way/procedure to service/clean the EGR valve? All over this tread the discussion is about cleaning the EGR pipe but nothing about the valve.
Thanks
 
#93 ·
art_arev said:
Jim, is there a way/procedure to service/clean the EGR valve? All over this tread the discussion is about cleaning the EGR pipe but nothing about the valve.
Thanks
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There is no cleaning of the EGR valve. If the tube was cleared or it was never clogged, then there is no alternative but to replace the valve if the code returns after being cleared.
 
#94 ·
Ok lets try this one more time:

1. What was the original code or codes that were set? p0400
2. Was the EGR tube clogged? Yes roughly 90%
3. Did you have a rough running eng. before you cleaned the EGR? no
4. What brand/make MAF did you install? Bosch
5. Is the CEL presently on? yes

I agree that i must have a vacum leak somewhere but am struggling to find it. I did break the tabs on the intake and am going to replace that this afternoon. It is tough to see but it does appear to be seated but that must be where the leak is coming from. in your experience, should i be able to hear the leak.
 
#95 ·
PW2037FXR said:
in your experience, should i be able to hear the leak.
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No you will not hear anything because it is not a vacuum leak.

It is unmetered air being sucked into the Throttle Actuator.

Before you go out and buy anything, buy a can of Brake Clean and while the truck is running at operating temp., spray it at the point where the hose gets attached to the Throttle Actuator.

If the idle increases you have found your problem
 

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#97 ·
FINALLY PASSED EMISSIONS!!! Thanks to 43sqd for the help. Now to come clean on the final remedy so hopefully it will keep someone else from making the same mistake. After using the brake cleaner and not finding any intake leaks i noticed the issue. I found my elusive vacuum leak and it was the black plastic "T" fitting that i did not install properly. It is a tight fit and hard to see everything in the back but no excuses on this one just missed it.
 
#98 · (Edited)
Check Codes said:
Image
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Another great thread for the DIY. Our ML320 (with 185,000 miles) popped a P0400 code 2 weeks ago that would not clear.

To determine if the EGR valve was good - I pulled the vacuum hose (arrow 1 in the photo) and connected a hand held vacuum pump. The EGR valve held a vacuum which meant the diaphragm in the valve was good. Additionally, you can see the stem and diaphragm move when vacuum was applied and released because of the open housing.

To determine if the EGR pipe was clogged, ran the engine (with MAF installed) at idle, and with the hand held vacuum pump tried to activate the EGR valve (after the smog pump stopped). If the plumbing was working, I expected to have the engine idle to stumble or become rough - there was no change when I applied vacuum to the EGR valve diaphragm.

Removed the EGR pipe and it was clogged. Cleaned, reinstalled and no CEL or pending code after 4 drives and 50 miles.

The air intake to the throttle body has a plastic level at the bottom that can be released by hand, just feel your way through it by pushing down.

I did not have to take down the coolant reservoir. Also tried to not remove the vacuum block above the throttle body, but could not get the pipe out. The vacuum block pulls straight up - pipe removal was accomplished after that. I also used Locktite threadlocker (blue) on the two pipe bolts to the engine.
 
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#99 ·
Not sure this is off topic but I have to ask this. I bought my 98 about 2 years ago and it had a 0400 code. 43Sqd replied about changing or cleaning the egr tube. No problems with doing that. However I had to do about a 400 mile emergency blast down the highway which somehow cleared the code which has still not come back after all this time. So questions are: would the tube still be blocked or did my trip clean it out enough to get below the sensor threashold? Or would this be from the egr valve having issues and also getting cleaned out?

It's not that I mind working on it but not sure if should wait until mine recodes or just go ahead and clean it reguardless. I'm at about 360K on mine (Just got my badge thingy from Benz) so no idea what to expect.
 
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