911 4S; power band not smooth; bad fuel filter?

[Dominic123]

I just purchased a 2004 911 4S with 41K; it has been running great then just a couple days ago it seems that it doesnt have the power that it used to have. Before it was a smooth power band going through gears; know it sort of floats or hesitates; I did notice that the low fuel light came on a couple times. Do you think that the fuel filter is dirty? I changed the air filter; no leaks anywhere.

I was pulling in yesterday and in first coming into garage and it seemed to make a very low pop or rumble sound.

Any suggestions or ideas?

Thanks

Dominci

[PTEC]

Doubtful. The fuel filter on your model were not designed to be serviced or replaced like the earlier 996s were. I would say a more likely culprit is your air mass sensor is on its way out.

[wvicary]

I would also suspect the MAF sensor but you need to monitor it's operation to see if it's at fault.

[Dominic123]

I would also suspect the MAF sensor but you need to monitor it's operation to see if it's at fault.

So how would I monitor its operation? Before when I would apply the pedal it was very responsive; now it seems sluggish and not smooth; auto parts store wants $120 for MAF and any porsche mechanic would charge that just to look; I do have an after market K&N intake http://www.knfilters.com/search/product.aspx?Prod=57-7000 ; not sure if that has an bearing on it going out; yet with 41K miles it seems rather early to go out.

Is there any spray of cleaner that I could use to clean it??

[Dominic123]

I would also suspect the MAF sensor but you need to monitor it's operation to see if it's at fault.

Ok; so I unplugged the MAF and drove about 5 miles and it ran great; good power and no issues; should I assume then that the MAF is bad or going bad?? Had no idea that they ran $390 just for the sensor!!

[Loren]

Yes, you can try cleaning it with a commercial MAF/sensor cleaner -- or just replace it. It's $4.95 for cleaner vs. $482.76 (MSRP) for a new sensor.

[Dominic123]

Yes, you can try cleaning it with a commercial MAF/sensor cleaner -- or just replace it. It's $4.95 for cleaner vs. $482.76 (MSRP) for a new sensor.

Just cleaned the MAF and letting it dry; it really didnt look dirty to me; I guess its a given its not a good idea to drive it with the MAF unplugged???

[Loren]

No, don't drive at high RPM without the MAF - besides getting a CEL the air/fuel mixture will be wrong at high RPMs (above 4000 RPM).

[Dominic123]

Porsche has been running great since cleaning the MAF; fires up great and smooth power band all the way through..

Thanks for the info guys.

Dominic