My first check engine light - at 50K miles

[geoff]

This may be the most basic question of all time. Yesterday I was driving from LA to San Jose and my check engine light came on for the first time (it's steady, not blinking, which I think is OK). Car [2001 986 5 speed, runs fine] has just over 50K miles and everything associated with the engine is completely stock. I wasn't even driving all that fast. All maintenance is current. I checked the gas cap (light came on after we stopped for gas) and it's tight. Now what do I do? Just go to Autozone or similar and have them read the code, then replace whatever is bad? I never paid much attention to discussions about OBD codes before because it never affected me. Anything likely besides an oxygen sensor or MAF?

Anyone in the San Jose area with a Durametric setup want to read codes the day after Thanksgiving?

This is the first car I've ever had where a check engine light comes on (other than several rental cars)

Edited November 22, 2007 by geoff

[Topless]

Yes. The CEL is very sensitive on these cars. Go to Autozone and read your codes for free or get your own pocket code reader for about $35. Once you have the error codes you can come back here and do a search. Tons of info. available to point you to the exact problem. Good luck.

[Tool Pants]

So, you only come up here for Thanksgiving.

Around the corner from the Porsche dealership I met you at 2 years ago is a shopping area called Santana Row. Your nephew will know it. In the back is a large parking lot and all sorts of cars show up every Saturday morning.

http://www.6speedonline.com/forums/showthr...520&page=82

Don't know what the turn out will be like after the holiday. I might go and if I do I can bring the PST2 and see what your Boxstir has been up to. You should go anyway. This is our version of Crystal Cove. You can talk to the former Boxster owners who now have the Italian stuff.

[pk2]

So, you only come up here for Thanksgiving.

Around the corner from the Porsche dealership I met you at 2 years ago is a shopping area called Santana Row. Your nephew ... This is our version of Crystal Cove. You can talk to the former Boxster owners who now have the Italian stuff.

Are you talking crystal cove in Laguna? I've heard of some goings on down there. When & where? Is there a life there for a lowly blown Boxster there?

Regards, PK

Edited November 22, 2007 by pk2

[GranburyChuck]

I had a check engine light show up a couple of times after filling up. Wasn't the gas cap. Both times went to Autozone and they read a P0430 (I think, cant remember). That is a high reading on O2 sensor bank 2 (or something like that). Last time it happened had it reset at Autozone and came back on the same tank of gas. Ordered a Durametric. While I was waiting for the Durametric I filled up again, different station and light went away. Never came back. Durametric did not show any codes when I got it. Both times light came on I filled up at a local station. I assume it was the gas. I don't fill up there any more.

May not help you now but something to consider

[geoff]

Thanks for all the suggestions so far. Here's an update so far:

First, I went to Autozone this morning, gave the guy my credit card for a deposit and grabbed one of their OBD readers. I've only seen pictures of these before, so this was all new to me. Fortunately, even an automotive spaz like me can use this thing. Pull it out of the case, plug it in to the OBD2 port under the steering wheel, turn on the ignition but not the engine, and scroll through the options. Codes show up on the LCD display, along with options to clear codes, tell whether the check engine light (CEL) is on, and an option to run diagnostics before taking the car in to be smogged. After reading the code(s), I cleared the code. The only code showing was P1130. The OBD2 reader said it was a fuel and air metering problem. I unplugged the OBD2 reader, put it back into the case and walked back in to return it and get my security deposit back. On a scale of 1 to 10 in terms of mechaincal difficulty, it rates about a 0. Even my wife could do this with me giving her directions over the phone. There is absolutely no reason not to do this if you're getting a check engine light

Back at my in-laws, I got online to renntech and looked up the P1130 code. It says "oxygen sensing adaption area 2 (cylinders 4-6), rich threshold". Then I searched for P1130 and got 3 pages of posts. The P1130 code usually shows up with P1128 (which did not show up), so possibilities according to Loren are:

Here are potential causes of a P1130:

– Incorrect signal from MAF sensor

– Fuel pressure too high

– Fuel injector leaking

– EVAP canister purge valve open

I rechecked the gas cap (it was tight), the oil filler cap (also tight), and dipstick (snug). In the past, the air/oil separator and oil filler tube were both replaced when the car was under warranty, along with doing the gas cap recall.

As near as I can tell, the odds are the mass airflow sensor needs to be cleaned or replaced (either that or there's a vacuum leak somewhere); more likely than an oxygen sensor. From what I can tell, the correct replacement MAF part number is now 996.606.125.01 (Bosch part 0.280.218.055 or B3130-160651). Can anyone please confirm this is the right part number. Does my DME need to be reprogrammed by the dealer to use this part?

Right now, the check engine light is still off after driving back to my in-laws from Autozone. I'll probably wait to see if it stays off (bad tank of gar), and then try cleaning the MAF.

Does this sound like the right approach? What else should I try? Is there any other information I could have gotten from the Autozone OBD2 reader?

Another question: what is the difference between the engine codes and fault texts on the ODB-II P-Code Menu?

Here's another issue: when I went to Autozone this morning, the engine oil display before I startred the car showed about half-way down. The car doesn't use any oil, and showed full before driving up here the other day. Could this just be moisture in the oil burning off from driving 400 miles (no excessive speeding involved), related to the check engine light (possibly MAF?), or something else?

Around the corner from the Porsche dealership I met you at 2 years ago is a shopping area called Santana Row. Your nephew will know it. In the back is a large parking lot and all sorts of cars show up every Saturday morning.

http://www.6speedonline.com/forums/showthr...520&page=82

Don't know what the turn out will be like after the holiday. I might go and if I do I can bring the PST2 and see what your Boxstir has been up to. You should go anyway. This is our version of Crystal Cove. You can talk to the former Boxster owners who now have the Italian stuff.

Jeff - the Autozone guy wasn't sure if the Santana Row get together was happening this weekend. He did warn me that it's right by all the shopping malls and it's Thanksgiving weekend, so traffic might be painful! Are you still planning to go? I'm not sure if I'll be able to get over there before we head home

[geoff]

And the answer so far seems to be ... bad gas :o

The check engine light appeared shortly after filling up (Chevron premium 91 octane with Techron, which I usually use). Mileage on that tank averaged about 24 MPG, mostly highway driving. I got to drive home very early this morning after a neighbor called to say there are more fires, so lots of highway driving. Once I filled up with the next tank of gas, my average mileage went back to around 28+ MPG on the highway, which is what I would have expected. No check engine light reappeared after I cleared the check engine light (around 400 miles ago). So I'll chalk it up to a bad tank of gas.

But back to my earlier question - can anyone confirm the correct MAF part number is 996.606.125.01, please

[1schoir]

And the answer so far seems to be ... bad gas :o

The check engine light appeared shortly after filling up (Chevron premium 91 octane with Techron, which I usually use). Mileage on that tank averaged about 24 MPG, mostly highway driving. I got to drive home very early this morning after a neighbor called to say there are more fires, so lots of highway driving. Once I filled up with the next tank of gas, my average mileage went back to around 28+ MPG on the highway, which is what I would have expected. No check engine light reappeared after I cleared the check engine light (around 400 miles ago). So I'll chalk it up to a bad tank of gas.

But back to my earlier question - can anyone confirm the correct MAF part number is 996.606.125.01, please

Geoff:

The part number that you have listed, 996.606.125.01, is ONE of the correct part numbers for the e-gas Boxsters, years 2000 trhough 2004. Best approach is to take out your current MAF and match up the part number to the new one you will want to order.

Take a look at the following link for a definitive list of the MAF part numbers, courtesy of Mike Focke: http://mike.focke.googlepages.com/checkeng...ssairflowsensor

Regards, Maurice.

[geoff]

An update After almost 2 tanks of gas, the Check Engine light came back (coincidentally, right after I filled up). After living with it for a few weeks, I finally took the plunge and opened the engine compartment up for the first time. It's pretty much the way the owners manual, Bentley and online instructions say to do it. It will probably take no more than 15 minutes the next time, and that's if I'm slow. Following Mike Focke's most excellent instructions at http://mike.focke.googlepages.com/checkeng...ssairflowsensor I pulled out the MAF and cleaned it with contact cleaner. The part number was 986.606.125.00.

Then I cleared the check engine light (only P1130, same as before) with an OBD reader I borrowed from AutoZone. And now I wait to see if the problem reappears in the next 400 miles or so. At least Sunset is having a sale on MAFs now! :)

[geoff]

Final (?) update: The new MAF from Sunset came and I swapped it in about 6 weeks ago. The check engine light still hasn't come back on in over 500 miles of driving. I took the car in to the dealer yesterday for the annual high priced oil change, and they reported back no codes. It looks like replacing the MAF solved the problem

I did notice after replacing the MAF my car started idling a little uneven, and at idle when putting the top up the idle stumbled once or twice. From what I found on here, idle issues on a car with 50+K miles are usually indicative of a gunked up throttle body, so I cleaned the throttle body the other week. It didn't look all that dirty, but the car idles just fine now. I have no idea whether there's any correlation between replacing the MAF and then having the idle start misbehaving or not, or whether it's mostly a function of the car getting to around 50K miles, but I guess the car is starting to get enough miles on it that a few more things will start needing attention at some point in the near future (is my motor mount the next to go?).