Mystery Check Engine Light?

[Halo]

I am usually a voyeur on this site (only 5 posts) but I thought my recent experience might have happened to someone else.

I bought a used MY99 Boxster about 2 years ago and really haven’t done much to it other than the scheduled maintenance, new tires, aftermarket stereo/speakers upgrade and DIY brake job.

This past Saturday I got my first check engine light. Not to panic, I told myself, now I have to purchase the Durametric software & cables to check the codes. As soon as I got home I made the purchase. I have been procrastinating this purchase for a while as I also have an airbag light on too. (not the first time, dealer replaced harness during 45K maint.)

I went to lunch today and guess what, NO check engine light? Will the Durametric be able to detect past events?

I am also wondering if faulty ignition switch can cause this anomaly? Funny things have been happening at start up i.e. turn the key, wait 3 seconds and it fires up but not all of the time, only once in a while. One morning it sounded like the battery was going die, which was a first.

I am not sure if these two events are related. I'll keep you posted.

Kind regards,

Halo

[Loren]

Depending on the fault it may have cleared itself or it might still be pending. Certainly worth looking at.

I would have the battery tested first, especially if it is 4 years old or older.

[Halo]

software and cable arrived today. I will post my findings.

Halo

[Halo]

UPDATE: here are my findings.

After searching other posts, it seems like I should start by cleaning my MAF sensor and see if it comes back.

As for my air bag light, the software allowed me to clear it without doing anything (cleared, no faults)

if it comes on again, I guess I'll have to clean the contacts and reset.

My battery, it is on 3.5 years old on a 85 month Interstate, I guess the previous owner did not want to mess with battery issues either.

Going to Autozone to have it tested to see how much life I have in it, while I pick up some Contact/MAF cleaner.

[Loren]

P1123 Oxygen Sensing Adaptation Area 1 (Cylinders 1 - 3) - Lean Threshold

This the mixture is too rich - but only on bank 1. Odd with the 1128 and 1130.

Hmm... MAF?

P1128 Oxygen Sensing Adaptation Area 2 (Cylinders 1 - 3) - Rich Threshold

P1130 Oxygen Sensing Adaptation Area 2 (Cylinders 4 - 6) - Rich Threshold

This says that DME can not make the mixture rich enough - that is, you have too much air getting into the engine.

Could be a bad MAF, a leaking AOS, or even a broken oil filler tube.

- Intake air system leaking.

- Fuel pressure too low.

- Volume supply of fuel pump too low.

- Fuel injectors fouled.

[Halo]

Loren, thanks for the quick reply.

The oil filler tube was replaced at 60k, probably not that.

I'll take a closer look at the AOS to see if anything is leaking or appears to be starting to.

The MAF was pretty dirty. I followed the procedure on Mike Focke's site, cleaned it, put it back in.

The wife and I just got back from a 40 minute, after dinner run on Pacific Coast Highway......no CEL lights.

Kind regards,

Halo

[Halo]

UPDATE:

to quote myself ftom an earlier thread, "I am also wondering if faulty ignition switch can cause this anomaly? Funny things have been happening at start up i.e. turn the key, wait 3 seconds and it fires up but not all of the time, only once in a while. One morning it sounded like the battery was going die, which was a first. "

well, my ignition switch died.

so after all it may have been a little of both things going wrong at the same time MAF (dirty) and ignition switch (failure).

BTW, CEL lights have not returned after cleaning.

Halo

[Pokerstar]

P1123 Oxygen Sensing Adaptation Area 1 (Cylinders 1 - 3) - Lean Threshold

This the mixture is too rich - but only on bank 1. Odd with the 1128 and 1130.

Hmm... MAF?

P1128 Oxygen Sensing Adaptation Area 2 (Cylinders 1 - 3) - Rich Threshold

P1130 Oxygen Sensing Adaptation Area 2 (Cylinders 4 - 6) - Rich Threshold

This says that DME can not make the mixture rich enough - that is, you have too much air getting into the engine.

Could be a bad MAF, a leaking AOS, or even a broken oil filler tube.

- Intake air system leaking.

- Fuel pressure too low.

- Volume supply of fuel pump too low.

- Fuel injectors fouled.

I had the 1128 and the 1130 last week, and while driving the CEL flickered and the engine felt like it was stuttering. It is new MAF time. That is where I would start. ('01 Boxster S w/ 103,000 miles)

[Halo]

Thanks for the input Pokerstar. I cleaned the MAF a while back and all is fine now, it was pretty dirty.

I used the MAF cleaner from Pep Boys.

no CEL lights yet.

kind regards,

Halo

[wams]

P1123 Oxygen Sensing Adaptation Area 1 (Cylinders 1 - 3) - Lean Threshold

This the mixture is too rich - but only on bank 1. Odd with the 1128 and 1130.

Hmm... MAF?

P1128 Oxygen Sensing Adaptation Area 2 (Cylinders 1 - 3) - Rich Threshold

P1130 Oxygen Sensing Adaptation Area 2 (Cylinders 4 - 6) - Rich Threshold

This says that DME can not make the mixture rich enough - that is, you have too much air getting into the engine.

Could be a bad MAF, a leaking AOS, or even a broken oil filler tube.

- Intake air system leaking.

- Fuel pressure too low.

- Volume supply of fuel pump too low.

- Fuel injectors fouled.

I had the 1128 and the 1130 last week, and while driving the CEL flickered and the engine felt like it was stuttering. It is new MAF time. That is where I would start. ('01 Boxster S w/ 103,000 miles)

(Wams - 09/09/2008) Several month ago, I had the same 3 codes on my '99 Carrera. I only replaced the MAF (procured it from Autohaus Arizona, http://www.autohausaz.com/), reset the computer and since then no more issues with MAF/O2 sensors.

[Halo]

I finally had to replace the MAF, seems to have fixed it.

I will check it with the Durmetric later in the month.

thanks everyone for the input.

Halo