The other day as I accelerated onto the motorway from the service station the PSM and ABS light came on. I pulled over and switched the engine off and when I started it again it was fine. Today as I accelerated the same thing happened again at about 5000 rpm in second gear. Any suggestions as a possible cause?
Problems when i accelerate.
- Thread starter childish
- Start date
Most likely the MAF sensor on the way out. What happens that the MAF sensor sends an implausible signal to the DME, and the PSM module can't make sense of it.
You could try cleaning the MAF, but if you have 40-50,000 miles on the clock you are on borrowed time with the MAF.
You could try cleaning the MAF, but if you have 40-50,000 miles on the clock you are on borrowed time with the MAF.
You don't say what model or year, but if it is a pre-facelift 3.4 996 with PSM, I'm assuming it is an early C4 or 2000-2001 C2. If so, the Porsche list price for the MAF is now a whopping £491 inc VAT, and it is a 5-minute job to change it. If you have a facelift 3.6, then they are £306. I would expect an indy to charge you less than that, as they will source cheaper alternatives, and hopefully pass some of the savings on to you.
Alternatively, try Euro Car Parts, as they are MUCH cheaper there, for the identical Bosch item. If you want to change it yourself, get yourself a T20 Security Torx bit. It's a doddle to do.
Alternatively, try Euro Car Parts, as they are MUCH cheaper there, for the identical Bosch item. If you want to change it yourself, get yourself a T20 Security Torx bit. It's a doddle to do.
The MAF sensor is mounted on the outlet pipe of the airbox, and is held on with two security torx screws. The picture shows the clip on an early C2, which is different to the C4 clip. On a C4, the clips are on the long sides, not the ends. It is much easier to undo the screws and remove the MAF sensor before taking off the connector, as you will be able to see the clips much more easily. Just unplug it, plug in the new one, snd screw it back on.
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I would call and check with ECP first. As you have found, they only list the Bosch numbers, but they also show two different numbers for coupe & cabriolet, which isn't correct. There are two MAFs for eGas cars, one for the 3.4s and one for 3.6s. I think that those are the two numbers they list, but it would be best to check with them before you part with your hard-earned.
Justin
If you haven't already got one, give this chap a try:
996.606.124.00 "" Bosch 0280 218 009 - £155.00 INC VAT
Postage = £4.50 INC VAT
Lloyd Deakin
Fuel Parts UK Ltd
Buntsford Hill Business Park
Bromsgrove
Worcestershire
B60 3DX
Tel: 01527 835555
If you haven't already got one, give this chap a try:
996.606.124.00 "" Bosch 0280 218 009 - £155.00 INC VAT
Postage = £4.50 INC VAT
Lloyd Deakin
Fuel Parts UK Ltd
Buntsford Hill Business Park
Bromsgrove
Worcestershire
B60 3DX
Tel: 01527 835555
Paul James
New member
Hi Richard,
I think I will be needing yet another MAF sensor - here are the symptoms;
- Both the ABS and PSM lights switching on randomly after going full throttle.
- Every now and then when at full throttle the engine will suddenly limit itself to whatever revs I'm at - I get a rough noise as if I'm bouncing off of a redline (just sounds a fair bit unhealthier). This can happen anywhere between 5000rpm > redline. The engine check light will then blink at me for ten or so seconds then go off.
I know that the ABS and PSM light situation is almost definitely the MAF - but is the rev limiting something more serious? Before you ask - yes, I'm ditching the K&N.
Cheers
Paul
I think I will be needing yet another MAF sensor - here are the symptoms;
- Both the ABS and PSM lights switching on randomly after going full throttle.
- Every now and then when at full throttle the engine will suddenly limit itself to whatever revs I'm at - I get a rough noise as if I'm bouncing off of a redline (just sounds a fair bit unhealthier). This can happen anywhere between 5000rpm > redline. The engine check light will then blink at me for ten or so seconds then go off.
I know that the ABS and PSM light situation is almost definitely the MAF - but is the rev limiting something more serious? Before you ask - yes, I'm ditching the K&N.
Cheers
Paul
Whaat you describe might well be the MAF. I had a similar issue before my MAF went out to lunch completely, in that when I accelerated hard in low gears the revs wouldn't drop off quickly when I took my foot of the throttle. No fault codes were registered. As soon as the PSM warnings came up it registered a fault, so I could confirm what the problem was straight away. When I changed the MAF the throttle response went back to normal. It would definitely be worth getting a diagnostic check done. Or if you have the inclination, you can buy an OBD2 code reader/scanner on eBay quite cheaply.
In case anyone else is interested, I got a price for all 3 available MAF sensors from Lloyd Deakin:
996.606.123.00 - £130.00 INC VAT & UK Postage
(3.4 models with mechanical throttle)
996.606.124.00 - £155.00 INC VAT & UK Postage
(3.4 models with M620 eGas)
996.606.125.01 - £195.00 INC VAT & UK Postage
(3.6 models)
996.606.123.00 - £130.00 INC VAT & UK Postage
(3.4 models with mechanical throttle)
996.606.124.00 - £155.00 INC VAT & UK Postage
(3.4 models with M620 eGas)
996.606.125.01 - £195.00 INC VAT & UK Postage
(3.6 models)
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