Christopher28

My '01 996 is running fine but seems to be getting lousy mileage. Is the mass air flow sensor a likely suspect? If it is, is a careful cleaning likely to solve the problem, or should I replace it? 2nd, the Porsche MAF on Pelican is listed at $753, while Ebay offers a range of manufacturers with prices from $250 all the way down to the low $20's - and even $16. Opinions? Last question; where the hell is it, on the engine... the videos...
(continued at bottom of photo)

on Youtube must be Boxters or 997's or the earlier model 996, because I don't see it where they show it. (I suspect it's in, or near the throttle body - still can't find it.) Thanks. PS. Dumb question of the day: I think I have the original radio, but can't find the **** letting me adjust the balance between front and rear speakers. The **** on the right side doesn't seem to affect it.

cds72911

Middle right edge of your picture.

sweet victory

You can buy a Genuine Bosch MAF on Amazon for $172.

https://amzn.to/2InhHbr

Porschetech3

If you just gonna throw parts on 19 year old car to get better gas mileage, throw 2 new Bosch upstream 02 sensors on it. It will probably do more for fuel mileage than anything else.

FrozenApples

I consistently get 14mpg no matter how I drive and am looking for ways to diagnose. I have a durametric. Is there a value I can watch that would indicate new upstream 02 sensors are old/bad and replacing them would help? I monitored the data and saw the typical sine wave. Other data:

• FRA ~ 1.07 on both banks
• RKAT is ~1.3 on Bank 1 and 0.15 on Bank 2
• MAF is ~20kg/h at idle
• Idle is ~800 rpm
• Camshaft deviations are about -3 degrees on each bank (working on bringing this down to 0)
• I have a KN CAI

2002C2

Hmm, that seems really low. For reference, I get around 23 mpg with a fair amount of acceleration mixed in with every tank. 2002 C2 3.6 MT not sure what to look for but am interested to hear what others have to say.

DBJoe996

Just as a point of reference, my engine runs great. I typically get 14-15 mpg around town, stop and go traffic, and 23-24 steady on the highway. I have gotten as much as 26-27 on the open road. I do tend to accelerate rapidly from traffic signals in first gear up to around 4000 rpm (after I'm warmed up). Just leaving the traffic behind. I really don't care too much about fuel mileage....it just is what it is.

jobyt

Start there. The KN Hot Air Intake™ is allowing the heated air from in the engine bay to be used. Go back to the stock air intake that pulls cool air from above the wing into the isolating box will result in a denser air charge.

FrozenApples

Makes sense. I've been keeping an eye out for one since I got the car. I guess I should be able to verify this is the cause though by monitoring my air intake temperature. I'll see if I can get some data and compare with whatever references I can find on the forums.

NuttyProfessor

Read your first sentence again slowly.

Try it with me... say it,

"My '01 996 is running fine" Good good...

again... "My '01 996 is running fine" Getting better...

AGAIN, "My '01 996 is running fine"

ONE MORE TIME LOUDLY! "My '01 996 is running fine"!!!!!

Now, how does that feel? Get off the computer and go drive and enjoy the car. You're sippin' the hypersensitivity kool aid. You don't buy a Porsche concerned about the fuel efficiency.

FrozenApples

I don't disagree. But if, for example, my 02 sensors are causing my car to run rich and therefore impact my MPG, fixing that will pay for itself in fuel savings and potentially save me from possible follow on issues of running rich. With all the sensors / data we have I'd hope I can diagnose a specific component clearly, so I don't have to waste money on just replacing things and seeing if there's improvement.

If I am being hypersensitive, then the data should confirm, and I'll go on my merry way filling up every 200 miles.

Christopher28

Ha ha - okay, I get it... I guess I'm with FrozenApples, though, thinking poor gas mileage could be an indication of some kind of issue that should be addressed.

Porschetech3

Using Durametric, select bank 1 02sensor voltage only, select graph display, should display a sawtooth up and down with 5 switches per second (new). Old, worn out, aging sensors will have a slow response as slow as once per second, and can even be curved pattern or delayed in switching.

Do same test for Bank 2...

Porschetech3

If you want to trade that K&N, I got an OEM air box I'll trade.

FrozenApples

Tech - thanks! This is exactly what I was looking for. I'll get the results early next week when I'm back from vacation. And I'll PM you about that swap as well.