90 C2 - Disconnected Oxygen sensor, fault codes and part numbers
#1
Racer
Thread Starter
![Question](https://rennlist.com/forums/images/icons/icon5.gif)
Hi All
I was just looking back throught the paperwork for my 964 when I happened across the following description of work carried out by an OPC
'CARRY OUT ENGINE ANALYSIS AND LOCATE FAULT CODES 23 AND 24. CHECK AND LOCATE FAULTS WITH KING LEAD AND IGNITION COIL. REMOVE AND REPLACE THESE ITEMS AND RETEST.. DISCONNECT OXYGEN SENSOR AND SET UP VEHICLE FOR NON OXYGEN SENSOR'
My Questions are:
1- why would the oxygen sensor be disconnected? Surely this would result in poor performance?
2- Is there anywhere on the net that I can find a list of fault code descriptions?
3- Ditto for Porsche Part numbers?
Thanks
Greg
1990 C2
I was just looking back throught the paperwork for my 964 when I happened across the following description of work carried out by an OPC
'CARRY OUT ENGINE ANALYSIS AND LOCATE FAULT CODES 23 AND 24. CHECK AND LOCATE FAULTS WITH KING LEAD AND IGNITION COIL. REMOVE AND REPLACE THESE ITEMS AND RETEST.. DISCONNECT OXYGEN SENSOR AND SET UP VEHICLE FOR NON OXYGEN SENSOR'
My Questions are:
1- why would the oxygen sensor be disconnected? Surely this would result in poor performance?
2- Is there anywhere on the net that I can find a list of fault code descriptions?
3- Ditto for Porsche Part numbers?
Thanks
Greg
1990 C2
#2
Racer
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Just thinking about the disconnected Oxygen sensor...... would this possibly prevent me installing an aftermarket performance chip?
Cheers
Greg
Cheers
Greg
#3
Racer
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
well I must be because I'm talking to myself again. Asside from that though I have now purchased an aftermarket chip but don't want to install it before I understand what running with no oxygen sensor means. Where are the experts?
![Confused](https://rennlist.com/forums/images/smilies/confused.gif)
#4
Burning Brakes
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Well, I'm no expert, but I think no O2 sensor means you'll usually run too rich, as I understand the system. Do you have a cat bypass? Often the bypass won't contain a port for the sensor so the shops just jumper the wires. It's generally considered to be a bad idea without having the engine control unit properly remapped for the change in conditions. Maybe that was done, maybe not. You may need to see what the heck you've got - chipped already, for example? I wouldn't start replacing bits, especially engine management bits, piecemeal, without knowing where you're starting from - that could get really ugly, and really expen$ive, really quickly...
Try doing a quick search on oxygen sensor - there are many threads, unfortunately, but some of them seem germane...
Try doing a quick search on oxygen sensor - there are many threads, unfortunately, but some of them seem germane...
#5
Technical Guru
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by gchristofi
'CARRY OUT ENGINE ANALYSIS AND LOCATE FAULT CODES 23 AND 24. CHECK AND LOCATE FAULTS WITH KING LEAD AND IGNITION COIL. REMOVE AND REPLACE THESE ITEMS AND RETEST.. DISCONNECT OXYGEN SENSOR AND SET UP VEHICLE FOR NON OXYGEN SENSOR'
Fault code 1_24 "Oxygen Sensor signal" -- The voltage levels for the O2 sensor are out of whack.
Originally Posted by gchristofi
1- why would the oxygen sensor be disconnected? Surely this would result in poor performance?
Originally Posted by gchristofi
2- Is there anywhere on the net that I can find a list of fault code descriptions?
Originally Posted by gchristofi
would this possibly prevent me installing an aftermarket performance chip?
![](http://members.rennlist.com/jandreas/DME-CountryCode-Jumper.jpg)
DME control unit Country code 3-pin plug
#6
Three Wheelin'
Join Date: Dec 2004
Location: Halifax, Nova Scotia , Canada
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
It is no more difficult to remap a non cat 964 than a cat model and in the UK it is far more likely that the aftermarket has this covered.Unleaded fuel was pretty late arriving !
It seems a pretty poor set up to run a 964 non-cat because it has a problem with lamda.Why not take it to someone that knows the cars and get that fixed ?
It is deep joy adusting the bypass screw on a flap unit to set idle mixture . Porsche didnt care about that because non cat ( no lamda ) is for usually for less developed countries !!
Geoff
It seems a pretty poor set up to run a 964 non-cat because it has a problem with lamda.Why not take it to someone that knows the cars and get that fixed ?
It is deep joy adusting the bypass screw on a flap unit to set idle mixture . Porsche didnt care about that because non cat ( no lamda ) is for usually for less developed countries !!
Geoff
#7
Racer
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Thanks for all the input guys and Jason, thanks for the detailed answers and the photo.
One thing is for sure, I'm not going to change the EPROM chip until I fully understand how the car is set up at the moment. I know it has still runs with the cat. My guess is that the O2 sensor malfunctioned and was not replaced due to cost. How much are they anyway?
One thing is for sure, I'm not going to change the EPROM chip until I fully understand how the car is set up at the moment. I know it has still runs with the cat. My guess is that the O2 sensor malfunctioned and was not replaced due to cost. How much are they anyway?