C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

Had tranny fluid changed and now getting P0170 and P0174

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Jul 19, 2014 | 07:32 PM
  #1  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
Had tranny fluid changed and now getting P0170 and P0174

I'm having a slight problem. My wife's '06 C230 was due for a tranny fluid change so I took it to a shop a buddy of mine used. He had what seemed to be a particularly complicated problem and it seemed like they were very thorough, finally getting my buddy's car going again. Now I'm wondering if they took so long on my buddy's car because they don't know what they're doing.

After they changed the fluid, the car drove home fine. The next morning, after startup from cold, it would have an oscillating idle - faster than normal and then slower. I had my wife shut it down and I checked to see if there were any codes - none. She drove it without incident the rest of the day. Today she said it did the same thing so she revved it a little and she said it started behaving again. This evening, we were coming home and the CEL came on. I read the codes (P0170 and P0173 each of them displayed twice(?). The scanner software says that one set of P0170 and P0173 are stored and the other set are pending. There didn't seem to be any driveability issues before the CEL came on (I noticed it just as we drove into the garage.

It seems that it could be a vacuum leak. I took off the air filter housing but didn't see anything obviously disconnected or damaged. From my reading of the procedure to change the tranny fluid, there didn't seem to be any vacuum hoses that would be disconnected.

Does anybody have any ideas?

Thanks!

Last edited by ncmudbug; Jul 19, 2014 at 07:37 PM. Reason: I had the wrong code.
Reply
Old Jul 19, 2014 | 07:46 PM
  #2  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
Ok. I thought there might be a vacuum leak because I looked up the wrong code! It seems that I need to clean the MAF. Does that seem right?

I'll try that tomorrow.
Reply
Old Jul 19, 2014 | 07:48 PM
  #3  
cm60k's Avatar
MBWorld Fanatic!
15 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
I think you have problem with fuel/air mixture, did you try to delete those codes..?

ZAYED,,
Reply
Old Jul 19, 2014 | 07:56 PM
  #4  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
Yeah. I haven't tried it yet. I Read further and found that it could be a vacuum leak after all if the MAF is good and clean.
Reply
Old Jul 19, 2014 | 08:06 PM
  #5  
cm60k's Avatar
MBWorld Fanatic!
15 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
Try to delete them, then switch the car off-on, then see if they will comes back or not...

ZAYED,,
Reply
Old Jul 19, 2014 | 08:06 PM
  #6  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
Update: I just took it for a short drive through the neighborhood and it seemed to drive fine. The only thing I notice was the idle was slower than I expected (~600 rpm) but it was smooth. So far, the codes have not returned.

Z, do you suspect that it will "fix itself"?

Last edited by ncmudbug; Jul 19, 2014 at 08:09 PM.
Reply
Old Jul 19, 2014 | 09:01 PM
  #7  
cm60k's Avatar
MBWorld Fanatic!
15 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
You may have loose in some place, MAF/air hose couplers, have to check those, during to gear oil changed, something been loose...!

ZAYED,,
Reply
Old Jul 19, 2014 | 09:53 PM
  #8  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
Thanks, Z! I'll pay particular attention to that when I take the MAF off to clean it.

It is pretty straight forward to take it off and put it on, right?
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Jul 19, 2014 | 09:55 PM
  #9  
cm60k's Avatar
MBWorld Fanatic!
15 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
Yes mate, you can tell..

ZAYED,,
Reply
Old Jul 20, 2014 | 10:31 AM
  #10  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Is the airbox clipped down firmly over the MAF? Indy's usually remove them for access & then don't clip them down tightly at the rear on the M272. This causes the MAF to hunt. Then you throw fuel trim codes.
Reply
Old Jul 20, 2014 | 12:16 PM
  #11  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
That doesn't appear to be the issue, Glyn. I popped it off looking for vacuum hoses that may have come loose and put it back on. I have been guilty of not clipping it down tightly in the past so I'm a bit more aggressive in checking that it's fully seated.

I'm going to have my go at cleaning the MAF today but this morning it had the same idle issue (oscillating between 800 and 1000) till it warmed up a little and then it was fine. So far no codes but if the condition isn't any better, I would expect them later if I don't do anything.
Reply
Old Jul 22, 2014 | 07:57 PM
  #12  
ncmudbug's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
 
Joined: Sep 2010
Posts: 1,434
Likes: 4
From: Raleigh, NC
2005 C230K, 2019 Honda CR-V, '74 Lotus Europa
Just thought I'd post an update.

I cleaned the MAF and the throttle body (for those contemplating this, there is different cleaner for each. You should be able to get it any reasonably supply auto parts store). The throttle body was difficult to get good access to because on the V6 engine, it is in the back near the firewall. An inspection mirror is really handy here. It seems the MAF includes the tube it's in. That confused me because all the pictures I'd seen looked like it would come out.

I put it all back together and it drove really well but the final test was when Mrs. NCMudbug took it out this afternoon because it was dead cold. The only problem was a squeaking brake! No CELs, not hunting on cold idle - or any idle for that matter.

Thanks Glyn and Zayed for your help!
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 02:21 AM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE