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Discussion Starter #1
Hello guys.
Unfortunately i had to replace my engine with another one, that was 3 months ago. About a month ago, i noticed that my car has a very very suck fuel comsumption. Literally, i bought 15 liters normal 95 Shell fuel, but i also tried with the more expensive one. (that is a little bit more expensive than the normal 95 fuel but not the vpower 100) So, i could go 120 km with 15 l, with my old engine i could ride about 8-9 l / 100 km consumption. The engine is the same 1.6 twin spark, AR67601. Also im using my old ECU beacuse with the newer one, my engine did not start cuz of the missing immo.
Has anyone experienced like that?
T.
 

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Any exhaust leaks upstream of the O2 sensor will hugely affect fuel consumption.

Was the O2 sensor removed from the exhaust or changed? What age is your car?
 

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I thought you may have an idea. If you didn't do it yourself, then either the person who did the work has caused a problem or strangely the O2 sensor has just became defective.

When the sensor becomes defective, it becomes slow to react to rich fuel mixtures which is why the fuel used can be twice as much! Unfortunately only Bosch sensors work quickly enough. Even the NGK/NTK sensors work too slow for smooth throttle response in the CF1 engine.

You say exhaust was changed. You didn't say if it is new or a 2nd hand one which came with the engine. If 2nd hand, perhaps the sensor which came with the exhaust was used. Alternatively, perhaps excess heat was used to change your O2 sensor into a different catalytic converter.

Why did you first state you changed the engine then state you don't know? Even a moderately interested owner would know what as done to the car. Anyway, I appreciate you tried to give information and I hope this helps solve your problem with the car.
 

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Discussion Starter #6
I thought you may have an idea. If you didn't do it yourself, then either the person who did the work has caused a problem or strangely the O2 sensor has just became defective.

When the sensor becomes defective, it becomes slow to react to rich fuel mixtures which is why the fuel used can be twice as much! Unfortunately only Bosch sensors work quickly enough. Even the NGK/NTK sensors work too slow for smooth throttle response in the CF1 engine.

You say exhaust was changed. You didn't say if it is new or a 2nd hand one which came with the engine. If 2nd hand, perhaps the sensor which came with the exhaust was used. Alternatively, perhaps excess heat was used to change your O2 sensor into a different catalytic converter.

Why did you first state you changed the engine then state you don't know? Even a moderately interested owner would know what as done to the car. Anyway, I appreciate you tried to give information and I hope this helps solve your problem with the car.
Yeah, i wasn't really understandable. I "replaced" my engine from a donor car on a Sunday. I also noticed that my old exhaust was in a really bad shape. I went to work on monday, and when i worked my 12 hour shift my mechanic friend replaced the exhaust for me.
By the way, which O2 sensor should i get? 'will replace it, we will see if it helps. I appreciate your help!
// phone/work //
 

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Bosch does seem to be the best brand. I dislike "fit genuine" type answers which may not qualify why but Bosch sensors do react quicker and O2 sensors do degrade with use/age and have a design life of 100000 miles but can last much longer.
New but cheaper O2 sensor can make throttle response hesitant. Degraded sensors cause excess hesitancy and high fuel consumption.

Sorry for being petulant. I need to work on my people skills.
 

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If the lambda is poor shape you'll have some hesitancy as you accelerate. Any hiccup around 1600-1800rpm is a sign that the lambda is struggling. My old 1.8 has an NTK lambda and it works okay.

Otherwise look at the MAF sensor. There shouldn't be any leaks around it and the connector should be tight. The plug has a yellow strap that you need to pull out before you can remove the plug.. and since these look strange if you don't know how to remove them, the mechanic might just have pulled it off, so it may not be connected properly now.

Your MAF may also have just packed up/got damaged from rattling around when it was off the car. If running with the MAF disconnected makes absolutely no difference, then a new one will sort you out. As above, try to find a Bosch one. A nearly new Bosch one is a better investment than a brand new Oochi-Chochi or whatever brand a "no brand" part is.


Ralf S.
 

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Discussion Starter #9
If the lambda is poor shape you'll have some hesitancy as you accelerate. Any hiccup around 1600-1800rpm is a sign that the lambda is struggling. My old 1.8 has an NTK lambda and it works okay.

Otherwise look at the MAF sensor. There shouldn't be any leaks around it and the connector should be tight. The plug has a yellow strap that you need to pull out before you can remove the plug.. and since these look strange if you don't know how to remove them, the mechanic might just have pulled it off, so it may not be connected properly now.

Your MAF may also have just packed up/got damaged from rattling around when it was off the car. If running with the MAF disconnected makes absolutely no difference, then a new one will sort you out. As above, try to find a Bosch one. A nearly new Bosch one is a better investment than a brand new Oochi-Chochi or whatever brand a "no brand" part is.


Ralf S.
Yeah, the hiccups are real. I tried with another MAF sensor, did not work better, i got even bigger idle around 1600 rpm which was ridiculous. Otherwise the engine is great, it pulls really good, but as you said there is some hiccup at round 1600-2000 rpm. // fruity, there is nothing to be sorry for. //
Thanks again guys, i will reply again about the problem solving :D
 
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