sigh.. CEL

[stateofidleness]

ok, so had some diagnostics ran, found out the oil separator was bad and had a vacuum leak... replaced the oil separator and now no more smoke and no more CEL's, BUT I still have a scary hunt for idle on startup...

tonight was the worst... started it (starts fine every time) and it started hunting right away, usually it will "catch" itself after like 5 seconds, this time it went on for a good thirty seconds and I heard some (hate to use the word "knocking"), but it sounded like the cars in the movies that run out of gas... heard it about 3 times (sounded like a "burp" or loud "gurgle" if that makes sense)

it only started doing that if i lightly rev'ed it to get the rpm's up.

mechanic said it might need some time after the AOS replacement to get back to normal.. but I had never heard my car make those noises before and the idle hunt was exactly the same as before the AOS replacement, just no smoke..

ONLY 53k miles!! WTF! i lose faith in Porsche's dependability a little bit more every day... when they're working, they're a blast, when they're not, it's the biggest pain in the ass.. and it seems like way more frequent than on other cars.. what gives??

[stateofidleness]

EDIT: could this also be caused by the MAF? I was going to attempt a "clean" before I had my mechanic do the AOS.. should I still do it? What is causing this wicked idle hunt?

[Bladecutter]

Originally Posted by stateofidleness

ONLY 53k miles!! WTF! i lose faith in Porsche's dependability a little bit more every day... when they're working, they're a blast, when they're not, it's the biggest pain in the ass.. and it seems like way more frequent than on other cars.. what gives??

Its time for you to step away from the car and take a couple nice, deep relaxing breaths. You are getting wound up too much about the car.

Yes, it is possible that it is the MAF sensor causing the issue, BUT you would be better off if you first started by cleaning the throttle body, since you had an AOS failure, there is bound to be lots of carbon build up on it.

I am sure that once you clean the throttle body, your hunting will be reduced, if not eliminated. If you want, you can even buy some MAF cleaner, and spray it down, too.

I have a '98 with nearly 89k miles on it, which I bought back in February, and I've put on 10k of those miles myself. I just had to replace the MAF yesterday on my car, because it went bad, and set off the P0102 code, and I checked its functionality with my Durametrics program, and saw that it was out of spec. That cost me $180 to replace, but its the first actual problem the car has had in the 10k miles I've put on the car.

I'm just glad I bought the Durametrics tool back in the summer so that when I needed it, there it was. If you don't have that, you might want to invest in it, if you are mechanically inclined, that is.

BC.

[stateofidleness]

maybe I will try tackling the TB and MAF cleaning tomorrow. I actually bought a can of MAF cleaner when I bought the scanning tool in preparation for the MAF clean so all set in that regard.

just.. the sound it makes at startup is SCARY lol... you know when you have a water bottle and you blow back into the straw to make bubbles, that's kinda what it sounds like, but ONE big bubble.

it did it again this morning, started it, let it run for about 5 seconds until i heard it happen, turned it off immediately, then restarted it immediately and it was smooth??? confused

really hope it isn't internal engine problems or something and something eas(read cheap) to fix

the fact that it runs great (even feels better now that the AOS was replaced) when it is warm means the internals should be fine right?

the startup thing is my only issue and after that "burp" i smell a STRONG gas smell from the tailpipe.. I had read that maybe its the air change over valve? I don't want to ruin the cats...

[stateofidleness]

checked and "cleaned" the MAF yesterday and it looked brand new. car is running top notch. go to start it this morning and minor hunt at idle again. last 3 cold starts were perfect, no hesitation or hunt at all.

half way to work, CEL comes back on (after 3 days of solid driving). Car is running great though.

so I guess my next step is to have the Air Change-over valve and the Electronic Change-over valve replaced.

I had read elsewhere that the Tiptronic models have an extra vacuum valve or something that can also go bad... since it requires taking the alternator out to replace these, I want to replace as much as possible all at once.

what can i expect to pay in labor? and should i replace the seconday air system hoses as well?

[Daniel R]

I have had all the same fun and games you are describing with my 2000S. It turned out to be an MAF on the way out and a pair of oxygen sensors in a really bad way, one so bad that that bank was bringing up misfire codes. When I replaced both the MAF and O2 sensors it was back to normal.

On a side note, if your car has been doing this for some time you may want to check the catalysts for damage. I switched to bypass pipes when I replaced the sensors as it was a less expensive option than new cats. I am now catless, as in Australia we only have to run one set of cats so the Boxsters only have the main cats and one set of O2 sensors.

Good luck.

[stateofidleness]

this all started within about a month.
tonight on the way home from work, i threw another code (only 1 this time)
p1128 which looks like a rich threshold on banks 1-3

i'm suspecting some kind of vacuum leak at this point but will have to dive in tomorrow morning. how does a "driveway mechanic" spot a vacuum leak? any tricks?

i was all ready to just have my air changeover valve and ECO valve replaced, but this code might indicate something different. I scoured the net, but haven't found too many people with just the ONE code, many had the accompanying 1130 code. What does having one code indicate?

*thanks for all the help and suggestions, hopefully i'll get her running top notch again soon*

[Bladecutter]

Originally Posted by stateofidleness

this all started within about a month.
tonight on the way home from work, i threw another code (only 1 this time)
p1128 which looks like a rich threshold on banks 1-3

I believe if you look for a vacuum leak, you will be looking in the wrong direction.
I believe that this code is going to point more in the direction of the two O2 sensors on that bank of the exhaust going bad.

When the exhaust passes through the headers and past the O2 sensors, the computer receives a signal that tells it if there is or isn't alot of Oxygen in the exhaust. If there's too much Oxygen, then the computer richens up the mixture. If there's too little, then the computer leans out the mixture.

Right now, the O2 sensors are saying that the one bank is running too lean, and the computer can't richen up the mixture for that bank any more than it already has, hence the CEL being lit.

If you replace those two O2 sensors, that will most likely resolve the issue.

Some recommend just replacing all 4 at the same time for the best results.

BC.