A few obd2 questions.
Discussion
Well I got myself a new toy to play with. 
A obd2 reader, using touchscan. But I have a few questions. A snip below.
Long term fuel trim, -14.06% seems quite high, the car runs ok, no warning / check lights, but is very thirsty for what it is (A twingo gt 1.2 tce 100, gets about 25mpg to 35mpg - but bear in mind this is mainly town driving, short runs etc). Short term fuel trim (bank 1, sensor 2) is always -100. (Although it might just be touchscan is saying there isn't a sensor 2).
A obd2 reader, using touchscan. But I have a few questions. A snip below.
Long term fuel trim, -14.06% seems quite high, the car runs ok, no warning / check lights, but is very thirsty for what it is (A twingo gt 1.2 tce 100, gets about 25mpg to 35mpg - but bear in mind this is mainly town driving, short runs etc). Short term fuel trim (bank 1, sensor 2) is always -100. (Although it might just be touchscan is saying there isn't a sensor 2).
A negative long term fuel trim would suggest that the engine is trying to lean itself out over a 'long' period of time. This means the O2 sensor is seeing a tendency towards a rich mixture.
Looking at your short term (bank 1 S1) the mean value appears more positive in value which indicates in the 'short' term it is richening the mixture, maybe to compensate for an air leak or your sensor is worn.
Looking at your short term (bank 1 S1) the mean value appears more positive in value which indicates in the 'short' term it is richening the mixture, maybe to compensate for an air leak or your sensor is worn.
Edited by Mikey G on Thursday 24th October 20:34
Might be fuel pressure regulator is on the way out (fuel pressure high), and long term fuel trim is compensating. I'd think that STFT at +3% and O2 voltage at 0.12 (ish) is consistent, and probably working OK, just the LTFT at - 14% is indicating some other issue. The data doesn't look too bad to me though, and seems to indicate that all the electronic stuff is working OK, at least on the face of things.
I think we found the problem, in the end up I asked a Renault tech to have a look at it. Pretty much its the previous owners fault.
The pipe from the intercooler to the throttle body was just a straight rubber pipe (it was oem looking to be fair. With a t piece between the throttle body, bov and the pipe itself.
The oem pipe is about half the diameter with a Inlet temperature sensor on it. So it was put back the the way it was when it came out of the factory. It idles a lot better, doesn't kangroo when cold, and seems far more torquey low down. Done this yesterday so I'll monitor it for a while, but I think it might have cured it.
Pc olly (previous owner) is a massive eejit.
The pipe from the intercooler to the throttle body was just a straight rubber pipe (it was oem looking to be fair. With a t piece between the throttle body, bov and the pipe itself.
The oem pipe is about half the diameter with a Inlet temperature sensor on it. So it was put back the the way it was when it came out of the factory. It idles a lot better, doesn't kangroo when cold, and seems far more torquey low down. Done this yesterday so I'll monitor it for a while, but I think it might have cured it.
Pc olly (previous owner) is a massive eejit.
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