Problems with O2 Sensor, Code 1114 and 1211

Hi all,

I had some problems with error codes and tried some things. As it brought up new issues I thought it would be better to create a new thread with more meaningful topic.

(old thread here:
http://www.ferrarichat.com/forum/348-355/407210-some-questions-error-codes-i-pulled-my-348-a.html )

So here is a bit of background around this:

I have an EU 1992 348 TS (and I adore it). I put in the check engine bulbs to see if something is wrong.
From time to time when I was on the Autobahn and pushing the pedal the 1/4 Check Engine light came up for 2-3 seconds and the disappeared again.
So I started checking the codes. There were some weird codes in there but most of them where gone when I either reseted them or when I cleaned the connectors.

So when I started to work last weekend I had the following situation when I pulled the Codes:

Drivers ECU (5/8): 4112 Stroke sensor
CoDrivers ECU (1/4): 4112 Stroke sensor, 4121 temp ECU CAT, 1114 O2 Sensor, 4114 TDC

So the stroke sensor/TDC were in because I guess we really did some stupid stuff with the car in a security training where the engine stalled often under strange circumstances.

Anyway - the 4114 and the 4112 where gone after a reset and never came again. So I dont worry about them right now.

The O2 and ECU CAT Temp errors stood there.

So last weekend I did the following:

-Screwed out both O2 sensors and tested them (according to a vid - just search for How To Test An Oxygen Sensor - Old Vs. New - in YouTube )
Result: Both O2 sensors went up to around 900 mV which means working (in my opinion)

-Exchanged the O2 sensors (right to left, left to right)

-Cleaned the cable connectors for both O2 sensors and the TDC sensor a bit and applied WD 40 (blew it out afterwards with pressurised air)

-Exchanged the CAT Temp ECU (right to left, left to right)


The result was - it made it worse:
The 1/4 check engine light is now on for 3-4 minutes.. then it disappears again and comes up again (not related to any frequency or driving style)...
Before that I only had a not nice Idle when the car was hot but now there seems to be some real error.

Anyway - I pulled the codes again and they were:

5/4 (drivers): 4444 (no error)
1/4 (codriver): 1114 (o2 sensor), 1211 (o2 sensor), 4121 (cat temp ecu)

So basically this means:

A) The o2 sensor is not defective because I a) tested them and b) swapped sides
B) The cat temp ecu is not defective because I swapped sides (anyone know how to test them? F. Exp heat the wire that goes to the CAT and then expect a voltage on a pin?)

To be sure it is not a ground problem I put a copper wire on the upper part of the o2 sensor on the codriver side and connected it to the frame - no change.

So C) No ground problem.

Also now the engine does stall when it is hot and in IDLE from time to time and when I really push the pedal on a mountain drive f.exp. I also have some power issues.

I would no start to check the wire diagram and see if there is a broken one bit somehow I dont believe it is the right track...

Any ideas???

Thanks,
Max

P.S: By the way - no error when the engine is cold. The 1/4 starts to illuminate after 10 minutes of driving or so. AFAIK this is normal since the O2 sensors have no influence if the engine is cold.

 

@plugzit
Do you really think it is the CAT itself? Would it then cause errors? I mean it is behind all that sensors. And also in general the car runs fine and pulls hard. It also would make no sense that after exchaning the o2 sensors the problem got worse... or does it?
Any way to test this?

I just exchanged the MAF's - same result
I also cleaned the connections for TPS, TDS, and the MAF. Didn't get any better.

I got light from time to time when I pulled those codes: 4121, 1211
Then I got constant light later on... pulled codes again: 4121, 1211, 1114

I think the 1114 was causing the constant light then...

Is there any good way of checking the connectors on the ECU while the engine is running? I find it a bit hard while its plugged in.

I really need help.. no idea where to look now. I could just change the O2 sensor but since the original sensor is now running on cylinder 5/8 and the one in now was before without any error it would make no sense too...

I am having a spare Top Dead Sensor (the Siemens HKZ100 thingy at home) - shall I try to replace it? Dont want to build in another error where there is none

 

Help

Here are some boring vids I made yesterday. Maybe you can correlate something between what I am doing while driving and what the light does... First vid driving on normal road and city, Second on Autobahn. There it stays on till i turned the engine off.

This one the lights only illuminate occasionally:
IMG4364 - YouTube
On from to:
00:02-00:09 (8 secs)
01:42-01:46 (5 secs)
02:27-02:35 (9 secs)
02:59-03:12 (3 secs)
03:26-03:34 (8 secs)

Then, on the same drive I drive onto the Autobahn 3-4 minutes later:
IMG4365 - YouTube
On from to:

00:59-01:34 (35 secs)
01:57-02:07 (10 secs)
03:23- end (till I turned the car off)

Maybe this helps?
As you can see even if the light is on the car pulls pretty good. The only thing I noticed is that in rare cases the engine stalls when IDLE on traffic lights for example

 

As often the problem sat on the drivers seat. Me.

While exchanging the o2 sensors from right to left and vice versa I somehow damaged them. Assuming that the right one must be okay brought me into this situation. I replaced the right o2 sensor with a new one and the failure is gone.

Thanks for your help!