NebulaStilo
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- Jul 18, 2019
- Messages
- 220
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2006 fiat stilo 1.6
Bought car without CAT.
I have spoke about my beast in a previous thread but since I replaced a few things i decided to make a new one.
Symptoms:
Rough idle at times until I switch it off then start again and will idle better with a slight drop in rpm
Hesitating acceleration most of the time,almost always.especially at lower rpm its more prominent. Once you hit 5th gear she seems to be better. At times though she accelerates no problem,no hesitation and other times she accelerates with hesitation right through the rpm range but mainly between pull away and 2500rpm
Ralf S on this forum explained another drive test where you accelerate slowly and steady throttle from around 1000rpm in 2nd and see what happens at 1800rpm. At 1800 rpm she hesitates therefore failing the test.
Kept at 1800rpm while driving she jerks continuously until you go give more throttle.
If you let off throttle completely while driving around 1800rpm she doesn't decellerate smoothly but harshly.
If you try to pull her flat foot right until red line,she won't go until the red line. She stops just under 5000rpm and stays there.
Poor fuel economy,normal slow driving in city and hardly stopping,she averages 8 to 9 l/100km.which for her is bad.
Diagnostics:
CEL is on and I get a p0141 code and no other. I read post CAT does not affect fuel trim(causing hesitation and slow acceleration etc)downstream o2 sensor readings shows no voltage AT ALL.I have a spacer on there too(previous owner must have put it on when removing CAT)
Upstream sensor has no code,I captured data and saw the sensor jumps around between 0.2 to 0.8. Not very erratic.
STFT jumps around pretty erratically though. It goes from -60 to 18 back to negative. She doesn't go much into positive but stays mostly in negative and at times she hits -100. That to me is very erratic. The O2 upstream sensor does not respond erratically like the STFT. That indicates to me its a lazy sensor which isnt setting a code. Am I right?
I have replaced :
Fuel pump
Spark plugs
Oil filter
Coil packs are all firing
* I had a k&n cone filter on and swopped it back to original box and replaced the panel filter in it with a brand new one
Timing belt and tensioner
Cleaned throttle body and crank ventilation(white liquid slime in crank ventilation) car doesn't use coolant,stays on max and no coolant in oil and no overheating(signs of blown gasket)
After replacing air filter I took her for a drive and same symptoms.
So what next can i look at? Is it the o2 sensor because all signs point to it? What else can I check?
I am going to replace the o2 sensors though. Besides o2 sensor where else can I check ?
And is the o2 sensor on 1.6 a wideband sensor?
These pics are during idle!
Thanks for the help
Bought car without CAT.
I have spoke about my beast in a previous thread but since I replaced a few things i decided to make a new one.
Symptoms:
Rough idle at times until I switch it off then start again and will idle better with a slight drop in rpm
Hesitating acceleration most of the time,almost always.especially at lower rpm its more prominent. Once you hit 5th gear she seems to be better. At times though she accelerates no problem,no hesitation and other times she accelerates with hesitation right through the rpm range but mainly between pull away and 2500rpm
Ralf S on this forum explained another drive test where you accelerate slowly and steady throttle from around 1000rpm in 2nd and see what happens at 1800rpm. At 1800 rpm she hesitates therefore failing the test.
Kept at 1800rpm while driving she jerks continuously until you go give more throttle.
If you let off throttle completely while driving around 1800rpm she doesn't decellerate smoothly but harshly.
If you try to pull her flat foot right until red line,she won't go until the red line. She stops just under 5000rpm and stays there.
Poor fuel economy,normal slow driving in city and hardly stopping,she averages 8 to 9 l/100km.which for her is bad.
Diagnostics:
CEL is on and I get a p0141 code and no other. I read post CAT does not affect fuel trim(causing hesitation and slow acceleration etc)downstream o2 sensor readings shows no voltage AT ALL.I have a spacer on there too(previous owner must have put it on when removing CAT)
Upstream sensor has no code,I captured data and saw the sensor jumps around between 0.2 to 0.8. Not very erratic.
STFT jumps around pretty erratically though. It goes from -60 to 18 back to negative. She doesn't go much into positive but stays mostly in negative and at times she hits -100. That to me is very erratic. The O2 upstream sensor does not respond erratically like the STFT. That indicates to me its a lazy sensor which isnt setting a code. Am I right?
I have replaced :
Fuel pump
Spark plugs
Oil filter
Coil packs are all firing
* I had a k&n cone filter on and swopped it back to original box and replaced the panel filter in it with a brand new one
Timing belt and tensioner
Cleaned throttle body and crank ventilation(white liquid slime in crank ventilation) car doesn't use coolant,stays on max and no coolant in oil and no overheating(signs of blown gasket)
After replacing air filter I took her for a drive and same symptoms.
So what next can i look at? Is it the o2 sensor because all signs point to it? What else can I check?
I am going to replace the o2 sensors though. Besides o2 sensor where else can I check ?
And is the o2 sensor on 1.6 a wideband sensor?
These pics are during idle!
Thanks for the help
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