Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 02-14-2006, 09:14 AM   #1
bmussatti
Guest
 
Posts: n/a
Good Q&A on Engine Codes P1128 & P1130

I saw this good Q&A today, and thought I would post it here for someone's future reference if doing a code search.

Here it is:


QUESTION:

DME indicated air/fuel mixture problem.
This came on after I ran Syntech feul injector cleaner.
I changed my fuel filter since and the engine light went off then came back on within 15 miles.
-
I talked with someone who had a problem with another car but syntech cleaner & they had to replace their oxygen sensor.
Any suggestions?
Thank you


ANSWER:

These faults are do the system has reached its maximum threshold to compensate for a lean system. This can be caused by either a bad or dirty MAF sensor in which you can clean or replace. Perhaps an intake leak in which would most likely be at the oil separator bellows. The last and not as common problem would be low fuel pressure or dirty injectors. I would get some good quality electronics cleaner and clean the MAF first. After that then you can get under the car and check the oil separator bellows for deterioration.
Scott Slauson - PCA WebSite - 2/12/2006


  Reply With Quote
Old 02-14-2006, 09:37 AM   #2
Registered User
 
Join Date: Sep 2005
Location: Minneapolis/St. Paul, Minnesota, USA
Posts: 3,308
Hi,

Interesting post, but the reply doesn't seem to consider the Lister's Cause and Effect.

I suspect that given the other person's similar experience with the same product, that it has something to do with the Injector Cleaner they used. That this Cleaner either has substances which contaminated the OČ Sensors reactive Ceramic, or burned much hotter, ruining the Heating Coils in the Sensors.

Subsequently, more Exhaust elements were able to condense on the Sensors rendering them incapable of producing an In-Spec electrical signal. The DME then interpreted these Off-Spec signals as a Lean Condition and one which exceeded it's maximum allowable threshold, triggering the CEL. In other words, I don't think he's running Lean, I believe that his DME has been tricked into thinking he's running Lean. Before I went tearing into the Bottom of the Engine, I would 1st eliminate this as a possible cause.

To be sure, dirty MAF or the introduction of additional, Unmetered, Air would cause a Lean condition just as the respondent states, but I don't think that's where the problem lies or the solution will be found. 'Course, either of us could be Right, or Wrong...

Happy Motoring!... Jim'99
MNBoxster is offline   Reply With Quote
Old 02-14-2006, 03:21 PM   #3
Registered User
 
Join Date: Sep 2005
Location: MARLTON, NJ
Posts: 539
Good info. I have a 1128 code on for the last few weeks. I have cleaned the MAF and reset the code... It came on about 1 week later again. History on the car is I have installed an Evo Cold Air Intake kit in September and changed the exhaust to B and B at the same time. No problems till about a month ago. I have suspected a fuel pressure problem at idle sometimes as I have a noisy or whining fuel pump. The car has 25 k miles on it and seemingly no service issues. The last thing I can do on my own is disconnect the battery to have the computer re-learn the mapping and hope for the best. I have run some fuel injector cleaner not too long ago and am not sure if this contributed to my CEL or not. It is frustrating even for me and I am in the auto repair business! My next stop is to a great local Porsche shop... Brother to Brother. Hopefully, they can check my fuel pressure/ injector situation and if no other problems are found, reprogram my engine management system to compensate for the increased airflow from the Evo intake.

Sounds kind of pricey!
I will keep you posted.
__________________
Joe DiMonte
2001 Boxster S
Triple Black
AUDIOGUY is offline   Reply With Quote
Old 02-22-2006, 12:28 AM   #4
Registered User
 
Join Date: Aug 2005
Location: The Bay Area
Posts: 14
I had both CEL for 1128 and 1130 after filling up; possibly having bad fuel at the local Chevron or due to a Octane Booster. After reading many threads, it seemed the problem might lay somewhere else. I tried cleaning the MAF and the throttle body, checking for vacuum leaks with little improvement. I ultimately replaced the MAF, erased the codes and the engine runs better. However I am currently experiencing a idle problem. It goes from 700 to 800 with the ac off and at idle. I thought I might just be paranoid but then the revving effect started happening when stepping on my clutch at low speeds. The revving occurs after every 2 - 3 stops. Now I am freaked out . I am in 1st and I am slowing down to a stop and disengage the clutch and the car revs to 1500 rpm. Help Please. Can it be due to my o2 sensors?

Last edited by vietoriouz; 02-22-2006 at 12:33 AM.
vietoriouz is offline   Reply With Quote
Old 02-22-2006, 01:22 AM   #5
Registered User
 
Join Date: Sep 2005
Location: Sacramento
Posts: 3,417
Send a message via AIM to blinkwatt
Quote:
Originally Posted by vietoriouz
I had both CEL for 1128 and 1130 after filling up; possibly having bad fuel at the local Chevron or due to a Octane Booster. After reading many threads, it seemed the problem might lay somewhere else. I tried cleaning the MAF and the throttle body, checking for vacuum leaks with little improvement. I ultimately replaced the MAF, erased the codes and the engine runs better. However I am currently experiencing a idle problem. It goes from 700 to 800 with the ac off and at idle. I thought I might just be paranoid but then the revving effect started happening when stepping on my clutch at low speeds. The revving occurs after every 2 - 3 stops. Now I am freaked out . I am in 1st and I am slowing down to a stop and disengage the clutch and the car revs to 1500 rpm. Help Please. Can it be due to my o2 sensors?
How many miles are on your car? And what year is it?
__________________
-99' Zenith Blue 5-spd...didn't agree with a center divider on the freeway
-01' S Orient Red Metallic 6-spd...money pit...sold to buy a house
blinkwatt is offline   Reply With Quote
Old 02-22-2006, 10:00 AM   #6
Registered User
 
Join Date: Aug 2005
Location: The Bay Area
Posts: 14
2000 S with 42k
vietoriouz is offline   Reply With Quote
Old 09-03-2007, 04:51 PM   #7
Registered User
 
Join Date: Sep 2006
Location: Los Angeles
Posts: 373
For me: P1128 + P1130 = dirty MAF

CEL with P1128 and P1130. I decided to reset the codes to make sure they weren't a fluke, drove it some more and they came back on again. Everything seemed fine. I reset one more time to be sure. And slowly but surely I began to get a little hesitation when revving the engine. So I cleaned the MAF, hoping like mad I didn't need to start replacing O2 sensors, and lo and behold the engine ran like a dream.

Not really sure why it had a problem, stock air intake and from what I can tell, the previous owner must have replaced it already.

__________________
1995 Silverado V8 - Green/Tan (FOR SALE)
2000 Boxster S - Ocean Blue/Graphite Grey
2002 GSXR750 - Blue/White
http://www.darkoven.com/sig.jpg
David N. is offline   Reply With Quote
Reply


Thread Tools
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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 07:56 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page