P1117, P1121, Po131, Po151, Po137, Po157 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

root_werks · 01-19-2010, 07:31 PM

Well, this could very well be my first post on the 986 Forum! Nothing like an introduction with problems.

I picked up my 3rd 986 a couple of weeks ago. Been struggling with this one a little. MAF is 3 years old, cleaned it with warm water.

O2's are about 1 year old, I did replace one of them, all codes remain.

I've been checking the harness, cannot find any broken or shorted wires, but I'm still working on that.

Any other places to start looking?

Replace the MAF anyway? I ordred my OBDII cable so I can run the datalog. That'll help as well.

Thanks for any help,
Dan

rick3000 · 01-19-2010, 08:53 PM

Welcome to the Forum!

And sorry you are already having problems. I don't mean to split hairs, but you said the error codes "remain". Did you reset the error codes after cleaning the sensors? The codes will not go away automatically once you fix it, you have to reset and see if it comes back.

root_werks · 01-20-2010, 07:08 AM

Thanks for the welcome Rick.

Yes, I did clear the codes after each trial. First was the PO151 O2 sensor for a new one. Cleared codes, came back after that 10-15 minutes of driving. Next was really checking as much as I could for harnes failure, air filter is very clean, washed MAF with warm water, let dry, cleared codes, came back same amount of time and same codes.

This is my 3rd Boxster and I have a data logger, but my buddy lost the cable. I have another cable on order now.

Cats have 100k miles on them......but you'd think I'd be pulling the high temp on the O2's, not the low temp?

Plugs and terminals look clean.

Could be a MAF still?
Oil seperator?

I also have my brake wear light on with 4 new sensors. I'm a little concerned there is a harnes issue. I haven't checked it all for sure, only a few parts that pass through something. I'm hoping someone else has had this failure and can chime in with some good ideas where to keep looking.

-Dan

Topless · 01-20-2010, 09:40 AM

Year, model, and mileage?

Those are not mixture codes that indicate a bad MAF. More likely:
1. Water damage to harness or DME.
2. Rodent chewed/damaged harness.
3. Wrong O2 sensors for car.

root_werks · 01-20-2010, 09:45 AM

Oh, sorry about that.

1997 2.5 5spd, no TC and no mods.

root_werks · 01-20-2010, 11:58 AM

Yuck:

"A contact at BOSCH who make the sensors for Porsche admitted to me that there are differences (even though the part numbers are the same!) between the ones sold in the aftermarket in BOSCH boxes and the ones sold to Porsche in Porsche boxes or bags. A genuine sensor from Porsche costs between £300 and £500 depending on the engine model, and the Bosch ones are much cheaper. However, the Bosch items tend not to last as long, are made/calibrated to lower spec's and fail much sooner than the Genuine parts. Its even been said that the ones sold in Bosch boxes are often ones which have failed Porsche quality assurance testing. Also a Genuine item comes with a 2 year garauntee from Porsche, even if installed by an independent specialist."

I am starting to think this is my issue. Mine is over 30k miles old. I'll have to check the reciept.

root_werks · 01-20-2010, 01:37 PM

After lots and lots of reading (I should be working) I've ordered a Bosch MAF, not the dealer one for $707, but one from parts store for $162. The dealer price of $707 is a little hard to swallow.

Seems my issues combined are pointing towards a failed or failing MAF. The ABS light along with the CEL codes certainly support this theory. I'll keep updates coming here.

Although the rodent or water theories carry a lot of merit. I'll start checking those as well.

Dan

yimmy149 · 01-20-2010, 03:36 PM

Hey root,

Since you are in Seattle, next time you need OEM parts, talk to: http://www.****************************************************.com/

Pretty much everything I've ordered from them is half the price of Barrier. Last I checked Barrier charged 30% over the "list" price, and Sunset is way under list. Plus since they are in Oregon it only takes a day or two for stuff to show up UPS ground.

-james

root_werks · 01-23-2010, 07:03 PM

Quote:

Originally Posted by Topless

Year, model, and mileage?

Those are not mixture codes that indicate a bad MAF. More likely:
1. Water damage to harness or DME.
2. Rodent chewed/damaged harness.
3. Wrong O2 sensors for car.

I'll start with the DME next. I'll do some searching, it's under the pass seat? I'll look and see where it is.

-Dan

cvhs18472 · 01-24-2010, 03:37 AM

I am only someone who has little true knowledge but two things stick out. One, couldn't water getting into the electrical system via cleaning the MAF with water be a place to start and , two- I have had repeating codes that would occur when I was trying to sort out a problem and they never came on in 5 minutes of driving. I thought it would have to go through a certain # of drive cycles. I have tried to locate problems, clear the codes, drove it once and when I got back I would read pending coded. It would not as yet show up as a CEL but it was logged in. The short version is that it might be a DME problem. Ed

root_werks · 01-24-2010, 02:02 PM

I took a look at the DME box today and cannot find any indication of water damage. I know it doesn't mean there isn't any or the DME box doesn't have issues, but it did make me happy everything around the DME and inside the rear trunk is really, really clean and no signs of water. I did remove it and plugged it back in some 30 minutes later. I haven't driven the car again yet, but I believe that resest codes by removing power from the box. Mostly I wanted to reseat the main DME connection. I'll drive and report back.

root_werks · 01-24-2010, 08:39 PM

Re-seating the DME didn't do anything.

There are a couple DME units for sale, $200-300. I certainly don't mind paying for one, but the dealer asspect worries me a little. How much could they charge for re-coding it to match the car? Yuck.

I'll keep posting findings, or lack of.

02-22-2010, 06:25 PM

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www.dieselinjection.cn

Yellow stone diesel parts plant was founded in 1997.Over the years,
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paulv · 02-23-2010, 05:02 AM

Quote:

Originally Posted by yellowstonepart

Yellow stone diesel parts plant is one of the leading manufacturers
of engine parts, in particular diesel fuel injection system
accessories for replacement, such as Fuel injection Nozzle, Plunger and
Delivery valve, ETC In south of china .

for more detail please visit our website : www.yellowstonediesel.com
www.dieselinjection.cn

Yellow stone diesel parts plant was founded in 1997.Over the years,
Yellow stone has grown and gained a reputation for producing
high quality products and delivering them on time.

Hey Yellowstonepart,

Porsche 戲汽車沒有柴油機 !

再見,

paul...

root_werks · 02-23-2010, 10:18 AM

Paulv,

It's just a guess on my part, but after replacing all 4 O2's now and all the other CEL's gone with only the P0430 present. I can now test and pass all 4 O2's so I am hoping it's just a bad Cat. I would assume so since the PO ran with faulty O2's for almost 3 years! I'm sure the Right Cat is clogged (ruined) and the left isn't far behind.

I found a pair of good low mile cats for $350 shipped to me. The 4 O2's, MAF, 2 front tires and lots of other little maint items have left my Porsche fund a little dry. Gotta water the money tree for a bit. Meanwhile, I'm trying not to drive the car much.

Upates to come....when I get some more money.

paulv · 02-23-2010, 10:53 AM

Quote:

Originally Posted by root_werks

Paulv,

It's just a guess on my part, but after replacing all 4 O2's now and all the other CEL's gone with only the P0430 present. I can now test and pass all 4 O2's so I am hoping it's just a bad Cat. I would assume so since the PO ran with faulty O2's for almost 3 years! I'm sure the Right Cat is clogged (ruined) and the left isn't far behind.

I found a pair of good low mile cats for $350 shipped to me. The 4 O2's, MAF, 2 front tires and lots of other little maint items have left my Porsche fund a little dry. Gotta water the money tree for a bit. Meanwhile, I'm trying not to drive the car much.

Upates to come....when I get some more money.

That code is for Bank 2 which is the driver's side (Bank 1 has the #1 cylinder in it and would have the P0420 code). If you have a buddy who owns or has access to an exhaust gas analyzer, you could measure all the gases (NOx, CO, HC, O2, CO2) before and after the Cat to prove it bad (or good). BTW, running with bad O2 sensors will make the car perform lousy as well as destroy the cats. Attached a little tutorial about exhaust gases.

Regards,
paul...

root_werks · 02-23-2010, 11:56 AM

This was a recent purchase for me (not my first Box though). It runs great and had no real notable change when the O2's were replaced other than the CEL's didn't come back. So there might have been a short in one of them? I didn't bother to test them after replacement.

420, right, sorry I was thinking engine orientation backwards, I should know that. I don't know anyone anymore that does the analyzing, but I'm sure I could track down a local shop that'd do it for a couple of bucks. Probably worth it. Why replace a cat when I may not need to?

Other thing I was going to try this weekend was swap O2's from side to side. See if I get a P0420 instead of a P0430. If I do, then I know one of my new O2's is probably bad.

So, still things to check. Good side is codes are different and there's only one now.