Boxster won't rev above 3000 RPM

[rprieto]

2002 Boxster S / Tiptronic won't rev above 3000 RPM:

I was unable to remove the MAF Sensor connector so I simply removed the whole thing and cleaned it with the CRC MAF Sensor cleaner. The sensor looked clean already btw.

Even with the MAF sensor off I could not figure out how to safely remove it.

After cleaning it and putting it back, no change at the 3K range. What bugs me the most is that I don't see the CEL even blink!

Engine idles fine and is running well up to 3000 RPM. Once at 3K, the engine cuts stutters till I back off the throttle.

Any ideas?

[Loren]

Does the CEL light up when you turn the ignition on? If not, the bulb is likely out.

Put a scanner on the car and check the fault codes.

All the symptoms point to a bad MAF.

[rprieto]

Does the CEL light up when you turn the ignition on? If not, the bulb is likely out.

Put a scanner on the car and check the fault codes.

All the symptoms point to a bad MAF.

CEL does light up when I turn the ignition on so I know at least the bulb is good.

The MAF is what I am thinking. I cannot figure out how to disconnect the sensor connector. I don't want to brake it. Is there a tab or something that needs to be pulled back or something?

[Loren]

Usually there is a a tab and/or a button that need to be pushed while pulling the connector off.

There are at least a couple versions of that connector.

[rprieto]

This is the photo I took yesterday of the connector using a mirror for a look at the back side.

How do I disconnect it?

http://www.flickr.com/photos/30713060@N05/...364281/sizes/l/

Edited November 17, 2008 by rprieto

[rprieto]

Usually there is a a tab and/or a button that need to be pushed while pulling the connector off.

There are at least a couple versions of that connector.

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!

[Loren]

If the CEL came back on then you still have a problem.

If it is the same fault code - then you likely need a new MAF.

[rprieto]

If the CEL came back on then you still have a problem.

If it is the same fault code - then you likely need a new MAF.

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.

[Loren]

Try the folks at Sunset Porsche (Porsche Parts at Dealer Cost). They sell the factory part for much much less than other dealers.

You could try try aftermarket Bosch - but a number of folks have had bad luck with those sensors.

[rprieto]

Try the folks at Sunset Porsche (Porsche Parts at Dealer Cost). They sell the factory part for much much less than other dealers.

You could try try aftermarket Bosch - but a number of folks have had bad luck with those sensors.

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:

[rprieto]

Try the folks at Sunset Porsche (Porsche Parts at Dealer Cost). They sell the factory part for much much less than other dealers.

You could try try aftermarket Bosch - but a number of folks have had bad luck with those sensors.

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.

Edited December 3, 2008 by rprieto

[juniinc]

I would drive her a bit more,,,then see

[rprieto]

Try the folks at Sunset Porsche (Porsche Parts at Dealer Cost). They sell the factory part for much much less than other dealers.

You could try try aftermarket Bosch - but a number of folks have had bad luck with those sensors.

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.

Edited December 13, 2008 by rprieto

[Loren]

Time to check the wire harness and MAF connector.

[rprieto]

Time to check the wire harness and MAF connector.

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