air fuel metering?

Basically on a cold 28 degrees Fahrenheit(sp?) night I was driving around and noticed when I pushed it... say around 3+k RPMs.. there's a very subtle shake/stutter I feel from the back. Hoses loose?

At first I thought I was losing traction, some sort of wheelspin, but then realized it has to be something else.

CEL was checked and reset..and as predicted it came back on when the car is pushed towards more spirited driving. Didn't push it any further than 4k or more...

Any ideas? Car is under warranty.. no mods except for Remus exhaust.

the codes are I think starts with P... 1128 and 1130 per my friend's OBD scanner.. air fuel metering.

Thanks in advance!

 

Probably the MAF sensor.
From the shop manual
117 P1130
361 Oxygen Sensing Adaptation, Idle Range, Bank 2 -
Below Limit
Diagnosis conditions
• Oxygen sensing system active
• Time elapsed after engine start-up: 250 to 350 seconds (USA)
• Time elapsed after engine start-up: 302 to 402 seconds (RoW)
• Engine temperature greater than 60 °C
Possible fault cause
♦ Incorrect signal from MAF sensor
♦ Fuel pressure too high
♦ Fuel injector leaking
♦ EVAP canister purge valve open

 

thank you... I'll be scheduling an appt. with Porsche.. feels good to use that CPO thing :-)

anyone think it could be some pressure thing with hoses? Maybe I should just replace them, along with the spark plugs.. maybe a trip to Tischer for Evo upgrades..

is it me or you think you're done but you use every little excuse to mod up

 

Ed is probably on the money here. Any time you throw both bank 1 and 2 02 errors the chances are the MAF is bad. If you have data logging you can check the voltage at idle and see if it is out of range. Normally the odds of both going bad is not likely. The MAF going south will create codes in both banks because the adjustments made are inappropriate to the situation. Both 02s then show the wrong data and it trips the code. The MAF is going bad at this point, but not completely failed.

 

I agree with everyone...in conclusion, the MAF is awefully common failure...dealer personel will probably pick it up immediately. I "think" that most of our 996 turbo owners have had this replaced under warranty. Boy...that one was easy.
Hey Stevey-that early turbo that was giving me fits....intake manifold was cracked under the air injection plug. some kind plumber inserted a pipe fitting there and it really wound up so far up me that I needed a proctologist way too much time on that one! M

 

odd... the check engine light went out by itself on my drive this morning. Could this be an anomaly? Didn't notice the stuttering.. but didn't have a chance to push it.

 

what obd2 data logging software to you recommend?

 

Any of the mainstream ones will work. I have custom software, but in the past have used Baum with my Palm Pilot. It works rather well and will chart several channels. I think the car chip will allow you to do the same you just need a laptop to down load the info.

 

so I take it to the dealer (HBL in Tysons, VA), and I tell them 1128 and 1130 before we reset the CEL. I was able to get the CEL to come back on. But odd thing is, they don't see the same codes which is why they say they took forever and with calls with Porsche to diagnose the MAF problem. I'm like, "why did it not show 1128 / 1130 codes again?". They said they didn't know. In any case they are ordering a new MAF and will install it tommorrow.

 

Myself, Lizard, and Zippy all use the pocketlogger. If you have a palm pilot (or other supported device) that is just sitting around gathering dust, you can pick up the software and cable for $129. Check to see if your device is supported on their site.

Here is a link to two threads that contain PocketLogger info:

https://www.6speedonline.com/forums/...t=pocketlogger

https://www.6speedonline.com/forums/...t=pocketlogger

 

unfortunately all three of my pda's are incompatible.

i already use the laptop as a datalogger with my zeitronix unit.

as long as i have the laptop in the front seat, i think i may give that AutoEnginuity a try. i hear good things about it. a little pricey though compared to the pocketlogger. wish i had a pda that would work with it.

 

You can pick up an older PDA on Ebay for $10-20 or so, if not less.