My car (156 2.0 TS year 2000) has been running rich for a few months now but passed the MOT on its second attempt (emissions) without changing anything other than a long drive before taking it there.
Yesterday all of a sudden the car has started 'kangaroo'ing' (can't think of a better way of describing it). I've got my foot down on the accelerator trying to do a constant 60 and then the car will suddenly stop accelerating for 1/2 second and then all power will return. Some times it does it just the once in say a 5 minute period but towards the end of the day (and this morning) it's doing it every minute.
I thought it was just doing it while keeping between 1,000 and 3,000 (rev) so this morning I tried staying in 4th gear along a 1 mile stretch of motorway on the way to work and it did it once at around 3,500. As soon as I was off the motorway and trying to drive around town the kangeroo'ing started again.
I read the codes last night and had P1172 - TRA autoadpt. parameter (multiplicative) SIGNAL TOO LOW
I have attached a photo of the decription if this helps.
I have hardly any knowledge of the parameters you can view in MultiScan (I only use it for error codes) but when checking the 'Lambda sensor status' while driving it flicks between Rich, Lean, Bottom Limit like a fruit machine spining! Although it does stick to rich most of the time which I already knew. When you release the accelerator pedal it doesn't say Rich and sticks to bottom limit. (I have a video if its of any use)
The video could be useful. If lambda signal stick to low or high limit, that's not OK. Check the heated status of the lambda also. Is it heated up well?
This error code means, that according to the lambda probe
the mixture is not OK
and the ECU is not able to produce the desired mixture strength, because it reached the limit of some control parameters (STFT, LTFT).
So, this means:
- lambda probe is OK, but mixture strength cannot be set by the ECU (MAF problem, air hose split, fuel pressure etc. and don't forget any split on the exhaust in front of the lambda probe)
- lambda probe is not OK, so the ECU would be able to set the mixture strength, but according to the bad lambda signal the ECU make continuous correction of the mixture strength
For example, I had this error code because of an empty catalyst (however it was a pre-cat sensor). But it's only one case, many kind of problems (and it's not sure that only one) can cause the symptoms.