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:( - Still no improvement! 1) I did a point to point on the MAF Sensor using the wiring diagrams on the Bentley book and all connections are perfect. 2) Reseated the DME connections hoping that might also clean any intermittent connections. 3) I ran the car with the MAF Sensor plugged in around the block. I noticed the rotten-egg smell probably due to a little too much for the catalytic converter. I decided to capture some of those values at the O2 sensors. By the way, there is no foul odor with the MAF sensor disconnected after returning from a test drive. 4) I re-ran 2 sets of driving test both with and without the MAF sensor plugged in and captured some data. Never once did I see the MAF sensor go to zero like I did before. However, I noticed voltages on the O2 sensors go to zero both with and without the MAF sensor plugged in. (Yes, I disconnect the battery after any changes are made to the MAF Sensor to reset everything.) As before, the car runs MUCH better with it UNPLUGGED! Can a disconnected MAF mask some other failure I am missing? Please help!

I have found that connecting the MAF, a new one, the car had problems with idle, acceleration...was due to a faulty 02 sensor so both cause an issue if one not working...disconnecting the MAF ironed out the problem...am having new 02 sensor fitted Tuesday What were the codes? Only today will I have time to get to this. Based on the graph I posted, I would think it to be more wire/connector related due to the rapid drops in voltage or MAF values seen. I don't want to event think about the DME. That and the whole engine wire harness are over $1K each. I am hoping to find an exposed wire rubbing against the car body or simply a bad connection at the MAF sensor itself. If not, I will disconnect the DME harness at the DME and reconnect. Did not seem easy when I was looking into that area last week. I'll also clean the MAF Sensor connector (connections) as well.

I captured these live values on my way to work. Stop & Go traffic and the car stalled when I got off the onramp (Tiptronic btw). The first chart focuses on spikes I see to Zero for the MAF Sensor. (236 to 283 range of the 2nd chart) You can see multiple places where the "Hot Film MAF" goes to Zero. (BTW: The "Mass Air Flow", not the sensor, I see fluctuates from values similar to the "Hot Film MAF" to values in the 200 to 300 range when the "Hot Film MAF" hits Zero. MAF Sensor Voltages, mostly seen in the 1.xx to 2.xx range, also goes to near Zero in sync with the Hot Film MAF values. The second is the whole sequence for reference. The third is what happened when I got off the freeway and the engine shut off. Looks like all data capturing stopped as well. Restarted the car and pulled over to disconnect the MAF sensor connector to get me to work. Does this hint to a possible wiring issue?

I captured both the MAF and the RPM while the car was parked, engine cold (accounts for slightly higher RPM at start). I noticed fluctuation of the MAF. Is this normal? Later today or tomorrow I want to capture live driving data to look to see if I can capture any engine stutter.

Funny thing. The CEL cleared itself. I wiggled the MAF sensor while capturing live data w/o a glitch. Drove around for a bit and the car twice hesitated from zero throttle. Just before the car hesitated I was hard on the throttle moments before. Wondering if there is a leak? Surely this is difficult to find if so.

I am using the correct MAF sensor. Both old and new have a diode.

I've not done a pinpoint test from the ECU. I measured voltages that appear to be valid before . Besides, Duramentric is measuring MAF sensor values.

"986 606 125 01" This matches what I removed. Car ran perfectly for a few days. I am just starting to run a few Durametric tests. Prelim test (2 days ago) indicate MAF to produce values 15-20 at idle (~700 RPM). Values are around 50 at about 2500 RPM.

Any idea if why all these codes are tied together? P0107 is a new one for me. The others are MAF related and it is new (Sunset). I was babying the car for a couple of days but got on the throttle turning left. Came to an idle then the engine missed briefly.

Regarding my 2002 986S / Tiptronic / 89K Miles So I've replaced the MAF Sensor and the Air-Oil-Separator (AOS). The MAF Sensor wiring seems to be good and the Durametric SW is recording changes at various RPMs. The car ran well for < 100 miles but today the engine missed here and there on my way to work. The CEL came on on my way home. Durametric SW indicates P0107, P0102, P1130, and P1128. I've just received the Durametric SW and I'd like to wiggle the MAF sensor connector with the engine using live data to determine if I have an intermittent connection. Ambient pressure records an unchanging "980" throughout my brief test period at various RPM ranges. (I don't know if that is good or not but a value is recorded). Let me know if need to capture something else with the Durametric SW to share. Thanks for the help in advance.

Will do tonight. Any single point failure or specific areas to check?

Replaced the MAF sensor with a 2nd new one from Sunset. Still runs bad but only slightly less. No codes yet but I'll bet I'll get P0102. Disconnected the MAF and again everything is OK! Anything else I can troubleshoot? Wiring, fuses, AOS? Anyone or any shops near Corona, CA? Otherwise I need to drop it off at a dealer.

Can anyone help me with this? I see a good number of readers... Is there a trick to disconnect the smaller rigid tube from the large tube entering the throttle body? Appreciate the help...

A photo would help. If you are referring to the thin rigid "J" tube that is runs from the AOS (Air Oil Separator) to the throttle body large tube, you just have to squeeze the outer ring that circles near the end of that tube and then simultaneously pull back the tube and it should come apart. Regards, Maurice. Here is a photo of my dirty engine compartment. Please let me know what folks use to clean it up. My finger points to the rigid connection point I am having difficulty with. I don't want to break anything. It does not give. Is there a trick to disconnect it from the large tube entering the throttle body?

The newer style AOS' still fail, just not as quickly and regularly as the older style ones. Air leak around the filter is certainly possible if the housing is not securely fastened, etc... There would be no harm in removing the plastic tube leading to the throttle body and taking a look there for any oil residue. That would help to confirm the bad AOS theory that the whistling might be indicating. Any more codes? Regards, Maurice. How do I disconnect the thin rigid tube entering the large tube before the throttle body? I can take a photo to further describe as I have the 3.2 L version. The Bently Manual is useless for that area since their photos are of a different model. I was able to pull away the large tube from the throttle body but only 1/2 inch.

I just cleaned the throttle body for the first time on my '01 2.7 this past weekend (yesterday - Sunday). Despite all the discussion on this in the past, I had trouble searching for the procedure for getting to the throttle body and removing it. Here's what I did: Loosened the hose clamps on both ends of the plastic tube [1 in your first picture] running from just past the MAF / air filter box [3] to the throttle body [2]. As you noted, the end [3] that butts up to the MAF comes off pretty easily. The other end that joins the throttle body i[2] s a real pain to get off. I pulled, twisted and wiggled for about 30 minutes, and somehow just got the right combination of moves and it finally came off. My hands aren't that large, but my knuckles are pretty beat up. I found it's easiest to access from the driver's rear fender side. Don't worry about the trouble getting it off, because it's even harder to get back on! I don't think it's possible to get the throttle body off without disconnecting the plastic tube at [2], but if there is, it would probably save half an hour or so. Same comment applies to reassembly. I haven't read about anyone using a blow dryer to heat up the plastic tube at [2] to expand it to get it on and off easier. I was going to try that if all else failed after a few hours. Somehow, the plastic tube just came off after struggling for a while. Once the black plastic tube is off, pull it out and set it aside. It was clean on the inside, but I wiped the outside down with several rounds of Simple Green, followed with water to get the Simple Green residue off. The throttle body comes off by unscrewing the 4 long bolts with a metric hex driver. The 2 long bolts on the driver's side have washers, and the 2 on the passenger side do not. Once you have the 4 bolts off, the throttle body is still connected with an electrical connector (e-Gas models), which simply unplugs. Pay attention to the orientation of everything. You'll notice on the throttle body there's an arrow that lines up with an arrow on the plastic air tube (visible in your second photo). Cleaning the throttle body is the easy part. Just keep spraying throttle body cleaner and wiping the crud off. You can push the flap open to get all the way through - it's spring loaded so watch your fingers. I also tried wiping down the tubing on the back side of the throttle body, but it was pretty clean inside (at 51K miles). The only hard part (as you would expect) is getting the plastic pipe [1] back onto the throttle body [2] after the throttle body is reattached. Expect another 30+ minutes of pushing, twisting, wiggling, swearing, etc. I lightly sprayed some silicon spray on a paper towel, then wiped it on the outside of the throttle body and inside of the plastic pipe. Hard to tell if it helped or not, but it didn't hurt. After everything is put back together, start you car and make sure everything runs and the throttle works before closing everything up. When I was all done, I gently re-tightened all the hose clamps since several felt semi-loose I don't think it matters how dirty the throttle body is on the outside for how your car runs! It's the inside that counts. But there's no reason not to clean up the outside when you have the throttle body out Working this as I write this. Looks like it will help as I am stuck. Thanks.

The newer style AOS' still fail, just not as quickly and regularly as the older style ones. Air leak around the filter is certainly possible if the housing is not securely fastened, etc... There would be no harm in removing the plastic tube leading to the throttle body and taking a look there for any oil residue. That would help to confirm the bad AOS theory that the whistling might be indicating. Any more codes? Regards, Maurice. Yes... P0102. I took it on the freeway for a nice run. Stuttered like crazy around 3500 rpm. This, of course, with the new MAF sensor! Came back, disconnected the MAF sensor and took it for another freeway run. Ran like a champ. Sunset Parts was closed today. So, I'm thinking the new MAF sensor is bad. What else could it be? Parked the car for another weekend.

AOS replacement is a fairly straightforward DIY, with only slight difficulty in installing the lower clamp on the bellows. There are a number of step by step DIY's on AOS replacement, both on Renntech and on Mike Focke's Boxster Pages. As to the whistling sound, take a look at this thread, where "RFM" confirms that it is a sign of a failing AOS if it occurs at low throttle: http://www.renntech.org/forums/index.php?s...mp;#entry124739 Regards, Maurice. I purchased the AOS today just in case as they close early. (Not yet installed as I am trying to isolate the problem.) My current AOS is the newer style. Q1: Do the new style AOS still go bad? I drained about 1/2 qt of oil and I replaced the Air Filter. The new air filter fit much tighter than the old and very dirty one. The car runs much better and there are no CELs. So... Q2: I am thinking there might have been an air leak around the filter. (Is that possible)? I've not taken it on the freeway yet so I'll see how that goes soon. But.... the whistle is still there. Happens even in park and again just a tad on the throttle. With the top off the sound is coming from the throttle body are and not the AOS side. A3: Should I be looking into the throttle body?

I noticed, while driving my 2002 986 S, 89K Miles, a whistling sound at low or easy throttle. Seems to be while in drive mode only. While at a light, or in any gear I can hear a whistle if I barely tap the throttle. Goes away if I am harder on the throttle. I only noticed this after replacing my MAF Sensor. Sound is more noticeable as I have not put back the fabric over the cover yet. I had a P0102 and replaced the MAF Sensor from Sunset this week. I think I still have a bad "new" MAF sensor as it ran immediately worse and threw. -> P1133: Oxygen sensing adaptation, lower load range, bank 2 -> P1126: Oxygen sensing adaptation, lower load range, bank 1 I went back in to look around for an air leak (visual only) and noticed one of the air filter latches was not attached properly and I snapped it back on. Ran slightly better, much less stuttering, but and I am now getting the original P0102 code with the new MAF Sensor! I am a new owner and had a pre-purchase inspection. One thing noted was Oil-Overfill. Can that (overfill) be the cause and I am seeing a ripple effect? If so I will do an oil change (myself) and look for leaks (air) & such. I am thinking I have 2 things going on, one still being a bad MAF sensor. I will try to isolate that this by tomorrow by disconnecting the sensor. Looking ahead, is R&Ring the AOS a DIY and has that been documented here? If I drain off some of the OIL will that fix my AOS issue? I've only find some bits of info here on the AOS. I am able to remove the oil cap with the engine on idle with no effort. When it is removed, I can hear it constantly "breathe" or suck air in. Is there an fault isolation procedure for the AOS? Will a bad one throw any codes? Frustrating beyond belief. I just wish I can simply drive. Big project going on and I only have late eves and the weekends. Thanks in advance for your advice!

Update on the MAF replacement: After the replacement the car ran better immediately! now with about 400 additional miles it continues to be flawless. Many thanks to Loren for his timely advice. Was you car running rough while throwing P1126 and P1133 codes? After installing a new MAF Sensor, my car ran worse and I went from P0102 (MAF) to P1126 & P1133. I'm thinking the new one is bad. Did you buy the new MAF on eBay? Lots of members have posted that they have bought defective MAF's both from eBay and from other disreputable sources. Your new codes may indeed indicate bad MAF. Regards, Maurice. Got it direct from Sunset. Found I did not lock down one of the air filter tabs. Car runs better and no codes... yet. New problem I hear is whistle sound at very low throttle. Been driving it around for 30 mins.

Update on the MAF replacement: After the replacement the car ran better immediately! now with about 400 additional miles it continues to be flawless. Many thanks to Loren for his timely advice. Was you car running rough while throwing P1126 and P1133 codes? After installing a new MAF Sensor, my car ran worse and I went from P0102 (MAF) to P1126 & P1133. I'm thinking the new one is bad.

I drove home, stop and go, and freeway traffic. Hesitates at low speeds. Better at freeway speeds but misses here and there and I can tell something is wrong. No CEL but I pulled the following codes: P1133: Oxygen sensing adaptation, lower load range, bank 2 P1126: Oxygen sensing adaptation, lower load range, bank 1 Did not throw those codes with the old sensor! Is my new sensor bad? I sent an email to Sunset.

Using an ODB2 Reader I pulled P0102 which also verifies the MAF Sensor. Sunset had a decent price ($266) and I R&R'd the MAF sensor this morning and reset the CEL. I drove it around the block and it seemed to be rough at first. The CEL came on briefly then, for the first time, turned itself off so I drove to work. 22 miles one way. I noticed what felt like some engine misses here and there and pulled over, disconnected the battery for 5 minutes, and continued on. Idled funny at first but settled down after 5 mins. Still however, there seems to be some hesitation at times when I get on the throttle. I did not have much runway (stop and go street traffic) for the remaining 5 miles. Is there something else I need to do like exercise the throttle? Is there a learning curve for the new MAF sensor? If so, how long? :help:

Cleared the code once more and it has not yet reappeared. I read that after 80K+ miles, erosion of the metal over time necessitates the need to R&R the MAF sensor. Makes sense to me. I feel the engine, at idle or slow speeds, seems to run rich. Is there a link for the best price on the original sensor? Appreciate your time and the help.

Success! I was finally able to remove the connector and drive the car to check the MAF. The car stuttered only slightly at ~3000 but never had a problem getting past that previous limit. I removed and cleaned the sensor very well with the CRC product. Although it still stuttered, very briefly at 3k, it pulled strongly into the "fun zone"... After removing the battery for ~8 to 10 mins, I later started the car and both the CEL went out and the stuttering, at 3000 RPM, went away as well. Since it was late I was only able to drive the car for 2 miles last night. However, on my way to work this AM the CEL came back on. Question: Do I need to have someone remove the CEL via ODB-II connectivity? Or, should I try to remove the battery connection once more to see if it clears again? Thanks in advance!