CEL behaviour - 986 Forum - The Community for Porsche Boxster & Cayman Owners

pidj · 08-24-2017, 05:28 AM

After months of experiencing a bouncing or surging idle (when warm at stop lights etc.) the ECU threw a P1130 code. So I cleaned the MAF sensor and checked the connections to the plenum/Throttle body. I cleared the code. I've driven about 300 miles and last night the CEL returned. I have not checked the code, but I'm assuming it's the same one. This morning I got in the car to head home and the CEL went out. The car is displaying no symptoms per se, but I find it odd the CEL disappeared. Is that normal behaviour for the 986?

Thanks!

DrCactus · 08-24-2017, 06:32 AM

hey there, if you look back a couple pages I have been having the SAME issue and same code. I cleaned the MAF and all sorts of things and still not found the issue. I have exact same car as you but Orient Red. Keep me updated by private message if you can figure this out and I will do the same

DrCactus · 08-24-2017, 06:36 AM

The code for me keeps coming back after a few days of driving each time I clear it... I even changed the engine air filter... no change.
This has been happening to me for a couple months now... all summer long

pidj · 08-24-2017, 10:07 AM

Well the code this time wa P0102 - which is more directly implicating the mass airflow sensor. I'm going to clean it one more time then see if that works. Otherwise I'm replacing it. Maybe that would help your situation?

Lapister · 08-24-2017, 03:29 PM

Had similar issue chasing it down. Maf was ok, vacuum leaks eliminated, then replaced pre O2 sensors both and problem gone. This at 65K. How many on yours?

pidj · 08-24-2017, 04:07 PM

Quote:

Originally Posted by Lapister

Had similar issue chasing it down. Maf was ok, vacuum leaks eliminated, then replaced pre O2 sensors both and problem gone. This at 65K. How many on yours?

29,000 miles (already had the 30,000 mile service done) ... I'm cleaning the maf for a second time and I'll look to replace it, should that not work.

DrCactus · 08-25-2017, 03:08 AM

I have almost 100K kms on my car... I cleaned my MAF sensor 4 times and still get the code P1130.

"pre O2 sensors both " Can you give me more information about this - link to where I can buy the part, part number, location on the car where I can find it? How to replace steps etc...

That986 · 08-25-2017, 03:51 AM

When people say "clean the maf" how are you actually doing that and what filters are you running?

DrCactus · 08-25-2017, 03:55 AM

Quote:

Originally Posted by That986

When people say "clean the maf" how are you actually doing that and what filters are you running?

Remove the MAF sensor and spray it with MAF cleaning solution (small can - similar to what WD40 looks like or compress air can to clean y our PC) a couple times - let dry and re-install... very easy and simple process. Takes just a couple minutes to do.

pidj · 08-25-2017, 04:50 AM

Quote:

Originally Posted by DrCactus

Remove the MAF sensor and spray it with MAF cleaning solution (small can - similar to what WD40 looks like or compress air can to clean y our PC) a couple times - let dry and re-install... very easy and simple process. Takes just a couple minutes to do.

Ditto here too. I'm going to disconnect it and clean the contacts too (ala Mike Focke's instructions) ... I'm running the OEM standard filter.

That986 · 08-25-2017, 05:23 AM

So not an electrical contact cleaner then that would completely evaporate?

If your MAF is getting that filthy that often then really I would looking into why it's happening as it shouldn't really get that filthy in the first place.

pidj · 08-25-2017, 06:00 AM

Quote:

Originally Posted by That986

So not an electrical contact cleaner then that would completely evaporate?

If your MAF is getting that filthy that often then really I would looking into why it's happening as it shouldn't really get that filthy in the first place.

Yes, I agree. Which is why I'm thinking it is either bad or improperly cleaned the first time ...

That986 · 08-25-2017, 06:51 AM

Quote:

Originally Posted by pidj

Yes, I agree. Which is why I'm thinking it is either bad or improperly cleaned the first time ...

Pop into your local radio shack and see if they sell a proper electrical contact cleaner.

pidj · 08-25-2017, 07:01 AM

I'm unable to actually detach the MAF from the connector. I've reinstalled it and putting pressure on the slide clips do nothing, as is putting pressure on the middle clip ... has anyone had success releasing this clip or is there a 'special tool' outside of your hands?
Thanks!

Nine8Six · 08-25-2017, 07:06 AM

^try what That986 said

And wear a facial mask, gloves (and a biohazard suit if you can). Same for any volatile and chemically engineered 'super' solvents lolll Stay safe always brothers

pidj · 08-25-2017, 07:09 AM

Quote:

Originally Posted by Nine8Six

^try what That986 said

And wear a facial mask, gloves (and a biohazard suit if you can). Same for any volatile and chemically engineered 'super' solvents lolll Stay safe always brothers

LOL! Great advice as always!!

Nine8Six · 08-25-2017, 07:12 AM

Quote:

Originally Posted by pidj

I'm unable to actually detach the MAF from the connector. I've reinstalled it and putting pressure on the slide clips do nothing, as is putting pressure on the middle clip ... has anyone had success releasing this clip or is there a 'special tool' outside of your hands?
Thanks!

No exp here, but quickly checked for you and nowhere to read that it needs special pressure/tooling. Got to be Bubblegum holding it. Extract taken from PP below

You need a T20 tamper proof Torx bit (inset upper left and lower left) to remove the mass air flow sensor from its home in the intake pipe (yellow arrow). It's typically easier to pull the sensor out of the intake tube first, and then disconnect the electrical harness. Be sure not to touch any of the sensor elements that are exposed (red arrow). Clean the entire housing area prior to installing your new sensor.

Source: Porsche Boxster Mass Air Flow Sensor (MAF) Replacement and Troubleshooting - 986 / 987 (1997-08) - Pelican Parts Technical Article

pidj · 08-25-2017, 07:41 AM

Got it. The connector on my car has one centre clip only. I had to carefully use a channel lock plier to remove it .... it's all good (or not)

Lapister · 08-25-2017, 03:14 PM

The Bosche O2 sensors for my02 was only about $42 a pair. You will have to cut old wire harness from old sensors and crimp onto new replacements because connectors are Porsche. Kinda shooting from the hip troubleshooting but that solved it. Up to that point I cleaned the Maf endless times and checked for vacuum leaks. @100k mikes they may just be marginal to throw that code off. I'd like to say it was a Bosche 15183 but you better double check.

Just another thought, if you are consistently throwing 1130 and not 1128 as well then it is likely that it's just one bank. By swapping Lft/Rt the code will likely change banks and then you will confirm the faulty sensor.

Boxstard · 08-25-2017, 05:56 PM

Went through the same issue a year ago shortly after I bought my car at 69K miles.

First tried to clean MAF a few times but did not do it, then I bought new one as it was cheaper than O2 sensors, still CEL kept coming back... so moved onto O2 sensors and under close inspection they were cheap no-brand with wires splined/ soldered in nasty way... so I bit the bullet and bought four O2 sensors, genuine Bosch with correct pigtail connecor, found the great deal with rock auto at $72 each, still not cheap when buying four but they did the trick!

I read that O2 sensor wires are supposedly designed to pass tiny air lengthwise under insulator jacket, so splining or soldering may affect sensitivity, true or not.... it made sense in my case.

PS. This past winter I battled another dreaded CEL issue due to bad check valve and switch valve in SAI system. Pain to get access to replace them but has been CEL free for the last 5 months, car running like a champ!!!