We're adding and testing new features:  Create your Garage, used it? Give us some feedback here.
Honda Civic Forum Home - Honda Civic Classifieds - Civic Photo Galleries - Create an Account

Go Back   HondaCivicForum.com > General Automotive > Mechanical Problems & Technical Chat
Sign in using an external account
Register Forgot Password?
Search



Welcome to the HondaCivicForum.com.
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread Display Modes
  #1  
Old 02-24-2008, 06:40 PM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default need help with p0170 and p0172 on 1998 Civic LX

Hi everyone !

I am in desperate need of a good advice from the conaisseurs.

I've got a 98 Civic LX (D16Y7 engine) back in July. Extremely well maintained and checked/serviced by the book(at Honda). To continue the history of good maintenance, in October I've realized it was the time for a new timing belt.
I went to Honda (different location) and they've done it. They recommended to replace the water pump too, and I agreed.
All went well until I drove home...
Check engine light came on for the first time. I went back to the shop and after many attempts to talk me down, they accepted to read the code.
It was P0170 and P0172.
Needless to say, they insisted it's just a pure coincidence and has nothing to do with their recent work on the car.
I've sent them to their origins and I left. I'll make sure nobody will go there for service anymore...
I eventually got the CEL reset and it didn't show up again until a couple of weeks ago. At that point I invested in an OBD2 scan tool, to be able to check the codes myself.
After 2 full days of reading tons of posts and the Service Manual, I am more confused than ever.
I'll be getting a new primary O2 sensor to replace the existing Denso, although I don't think is necessary (correct me if I am wrong).
When checking the O2 sensor I've noticed a CRACK in the exhaust manifold, exactly above the sensor. I haven't removed the cover to see the extent of the crack, but I am wondering if it has something to do with P0172 system fuel too rich ???

The readings at idle are:

Coolant 190 deg F
ST FTRM -17.9
LT FTRM -15.6
MAP 10.6

Eng RPM 749
IGN ADV 12.0
IAT 73 deg F
ABSL TPS 9.8%
O2S11 0.2-0.8 (fluctuating)
O2S12 0.855 (steady)


I've just noticed the idle not being quite a purr either, but a little shaky.

Please excuse my extra long post, but I guess more details will help an educated opinion.

Thank you in advance.
Reply With Quote
  #2  
Old 02-24-2008, 07:05 PM
RonJ's Avatar
Recognized HCF Member
1997 Honda Civic
 
Join Date: Sep 2007
Location: Houston, Texas
Posts: 9,450
Default RE: need help with p0170 and p0172 on 1998 Civic LX

Is the other code P0171 (running lean) rather than P0170?

If the crack is allowing outside air to mix with exhaust gases near the O2 sensor, then you could get code P0171.

Contact Honda to find out whether your Civic is covered under the Emissions Warranty, which pertains to some Civics up to 150K miles or 15 years.
Reply With Quote
  #3  
Old 02-25-2008, 03:25 AM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default RE: need help with p0170 and p0172 on 1998 Civic LX

Hi RonJ and thanks for the reply, but the codes are clearly P0170 (fuel trim malfunction-bank1)and P0172 (system fuel too rich-bank 1).
Reply With Quote
  #4  
Old 02-25-2008, 05:07 AM
RonJ's Avatar
Recognized HCF Member
1997 Honda Civic
 
Join Date: Sep 2007
Location: Houston, Texas
Posts: 9,450
Default RE: need help with p0170 and p0172 on 1998 Civic LX

I was not able to find code P0170 in the 96-98 Civic service manual. Perhaps it's a generic scan tool code redundant with P0172?
Reply With Quote
  #5  
Old 02-25-2008, 05:58 AM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default RE: need help with p0170 and p0172 on 1998 Civic LX

The same codes were read by the Honda technician, back in October and I know is not in the manual..

I think P0170 (fuel trim malfunction) is just a pending code, sort of pre-code, until the computer gathers more info to pronounce the actual fault code, which is P0172 - fuel system too rich on bank 1 (in my case).

I don't know if it matters or not, but last night I clamped the vacuum hose on the fuel pressure regulator while running at idle, just to see if it makes a difference. It made no difference !!! I have a feeling the regulator might be stuck open, but I don't have the gauge to check the fuel pressure.

What do you think?

Reply With Quote
  #6  
Old 02-25-2008, 10:00 AM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default RE: need help with p0170 and p0172 on 1998 Civic LX

Any other ideas or suggestions ?
Reply With Quote
  #7  
Old 02-26-2008, 11:07 AM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default RE: need help with p0170 and p0172 on 1998 Civic LX

I ended replacing the spark plugs, last night. The idle is back to the normal PURR without being shaky, but still haven't got rid of the P0172 code...

HELP !
Reply With Quote
  #8  
Old 02-27-2008, 02:24 PM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default RE: need help with p0170 and p0172 on 1998 Civic LX

Update:

Now it's getting even more interesting. The engine stalls when I stop at traffic lights, after driving a while, so it's more than warmed-up....!
What the heck is going on ?!

The code remains consistent, unchanged at P0172 system fuel too rich on bank 1.

I need some help, 'cause I'm going nuts.
Reply With Quote
  #9  
Old 02-27-2008, 02:37 PM
RonJ's Avatar
Recognized HCF Member
1997 Honda Civic
 
Join Date: Sep 2007
Location: Houston, Texas
Posts: 9,450
Default RE: need help with p0170 and p0172 on 1998 Civic LX

Again, the cracked manifold may need to be replaced.

In addition, other possible causes for P0172 are:

Click the image to open in full size.
Reply With Quote
  #10  
Old 04-11-2008, 05:37 AM
x33 x33 is offline
 
Join Date: Feb 2008
Posts: 7
Default RE: FIXED ! need help with p0170 and p0172 on 1998 Civic LX

Ok I am returning after days and days of frustation...and work.

I have checked everything that the service manual indicated as a possible cause (RonJ posted the list above, as well) and after replacing the fuel pressure regulator, EVAP purge valve and O2 sensor, even PCV valve (thanks Ebay !!!), the car was doing exactly the same thing !!!

Oh well, it's good to know I have some spare parts, now.

Just before getting to dig out the injectors, I went with my gut feeling and popped out the valve cover to check the valve clearance.

Sit down and be amazed.

The morons at Honda service tighten the valves so bad, I am surprized the engine still worked !!! They were at less than half the MINIMUM clearance required by the book, on both intake and exhaust. I don't know if it was done on purpose, just to milk some more money, or they are complete retards...

Anyway, I am posting this for everybody else out there, who (perhaps) ignores the importance on valve clearance, specially on Honda engines.

Good luck everyone and feel free to ask me any questions regarding my long and intricate adventure with this type of error codes.

Cheers !
Reply With Quote
Old 04-11-2008, 05:37 AM
 
 
 
Reply

Tags
1998, 98, civic, clearance, cracked, d16y7, dx, ebay, gap, manifold, p0170, p0171, p0172, rich, valve

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


LinkBacks (?)
LinkBack to this Thread: http://www.hondacivicforum.com/forum/mechanical-problems-technical-chat-8/need-help-p0170-p0172-1998-civic-lx-61382/
Posted By For Type Date
Honda Civic Codes P0170 P0172 This thread Refback 06-25-2011 06:09 PM

Advertising

Featured Sponsors
Vendor Directory
Our Sponsors
Civic Custom Rims
AMSOIL - Performance Oil Technology
K&N Engineering
Advertise Here
All times are GMT -8. The time now is 12:20 PM.

Internet Brands, Inc.
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.


Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for HondaCivicforum.com content, comments, or advertising. HondaCivicforum.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse HondaCivicforum.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.