Geldfalle 944

Ok.. So here goes. 88 944 N/A

limit / my reading
HC 2.00 2.8462
CO 20.0 16.14
CO2 364.8184
NOx 4.00 4.144

While I do work at a Porsche Audi dealer I trust your word just as much.
Anyone else run into these readings? Any Suggestions?

What I have already done:
FI service
Spark plugs
air filter
Cap Rotor
Plug wires are fairly new

When I first start it up I get a bit of smoke but it goes away, stumbles a little when cold but quickly goes away as it warms up.
I can smell it is running rich. No history of the cat being replaced. Not sure if this will help.

krystar

damn...high HC and high NOx too rich and lean.

probably start with cleaning fuel injectors, check your o2 sensor, check spark plugs. cheap things first.

Geldfalle 944

Thanks. I was editing as you were typing. I have not replaced the O2 sensor. I will check my database to see if that has been done.

krystar

the oem part is probably really expensive, even at dealer costs

Geldfalle 944

Checked my database, plug wires and fuel injectors done about 60k ago. No history of cat or O2 sensor.
Car has 224,000 miles. I am beginning to think I need a o2 sensor and cat.

V2Rocket

wouldnt hurt to run some FI cleaner through there anyways, but yes o2 at the least, if it comes back with a high NO count youll want to do your cat too

Don 944 LA

replace O2 sensor. Will pass even with old cat usually.
OEM or generic depending on wallet size

Geldfalle 944

Found local O2 sensor for $130. Will throw it on there and toss it on the 5 gas analyer at work to see where I am at. Other thing I forgot to mention is it seems to only run really high when driving normal. IE at highway speed the HC went really high. Makes me think of the O2 sensor even more.

Don 944 LA

advantages of working at a dealer, access to gas analyzer .... must be nice

Geldfalle 944

You guys are a even nicer resource. Considering pretty much every owner in this forum has dealt with this problem on some level.

GTSilver944

There's a $20 universal O2 sensor that's the same except you need to splice the wire instead of plug and play. Lemme see if I can find the link to the part number.

Edit: There's a better page that has the info somewhere but this has it too: https://rennlist.com/forums/924-931-...placement.html

Geldfalle 944

Ok.. update.
Got a new O2 sensor from world pac for $114. I do not trust the universal one, I am a picky mechanic and do not like splicing wires.

Our gas analyzer measures in PPM and the Etest is in GPM. Anyone know of a converter for GPM to PPM?
I did take a reading prior to installing the O2 sensor so I would have a comparison. Once installed I tweeked the AFM and the throttle while watching the readings. Found a pretty good balance between NOx and HC but it still smells rich to me.

V2Rocket

check your fuel quality switch to see if its been messed with at all

JohnKoaWood

You guys with your silly emissions tests...

set FQS to position 2 or position 6 and try again!

http://www.motronic.ws/fqs.htm

2 is 0 timing change, -4% fuel, position 6 is -4% fuel and -4.15 deg timing

also check to see if your car has other than stock chips in it... some of the aftermarket chips run rich!

Geldfalle 944

I have been putting premium in, 91 octane out here.
You make it sound so easy John.

I have to remove all my VW Audi knowledge and approach this with a clear head.

Where exactly is the FQS? In the ECM?