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Daewoo Matiz 1.0 2004 Lambda question

Posted by Peter Holland User icon on December 2, 2008, 3:59 pm

This car has now had three lambda sensors fitted, the last one was a genuine item, but after about a week it logs fault code P0133 02 sensor B1S1 value change too slow. Freeze frame data as follows.

RPM 2080
MAP 47 KPa
Speed 49 KMH
STFT 3.9
LTFT 3.1

Scoped sensor outputs.

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Shown at idle

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Shown at 3000 RPM

I'm not very happy with this trace but I'm stumped as to what could cause it. I would of expected it to switch faster and it doesn't look very clean. I'm thinking this could be a software issue. Any comments?

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Steve User icon on December 2, 2008, 5:53 pm, in reply to "Daewoo Matiz 1.0 2004 Lambda question"
Steve Shaw

has the sensor got a good earth connection?

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Peter Holland User icon on December 2, 2008, 9:33 pm, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"
Peter Holland

Checked earth to sensor, heater circuit etc and all seem ok. The car has only done just of 20k miles as well.

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Darren Jones User icon on December 6, 2008, 6:06 pm, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"
Darren Jones

Hi peter, i dont know these Daewoo's very much but at 2000 rpm i would of like to see a higher vacuum than 470 mbar & if this car runs a MAP sensor as the load sensor this would cause the engine to go rich which is what the scope reading is showing at 3000 rpm,so maybe slightly block exhaust, cam timing, vacuum pipe to map sensor if fitted, blocked air filter, EGR valve stuck slightly open or the MAP sensor its self
hope this helps Darren

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Dave Harney User icon on December 6, 2008, 7:49 pm, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"
Dave Harney

Hi Peter,
Could you scope 02 sensor and MAP sensor together, showing them both at idle, then WOT then back to idle ? maybe with TPS too if you have enough channels.

Regards
Dave

You can trim a sheeps wool many times, but you can only fleece it once !

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Kevin Apps User icon on December 6, 2008, 10:03 pm, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"

Peter
If some work has been carried out (even a service) are the VAC pipe,s back correctly ?
Kev.
ps i mean fitted where they SHOULD be.

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Peter Holland User icon on December 9, 2008, 7:40 am, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"
Peter Holland

Thanks for the replies, but the customer wanted his car back before I had time to carry out any more tests. I'm waiting for him to contact me so that I can get the car back. I'll keep you informed.

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Peter Wright User icon on December 11, 2008, 2:29 pm, in reply to "Daewoo Matiz 1.0 2004 Lambda question"
Peter Wright

Peter.

If you look at the trace at 3000RPM, its staying longer on the Rich side that it is on the lean side. Why?? Its seeing a LEAN mixture so its sitting in the rich side for a longer period of time trying to richen the mixture up to achieve Stoichiometry.

Your STFT and LTFT agree with what the O2 sensor is showing ie. they a positive (adding fuel).

What the code is telling you is that the cross over times are too long ie. its in the rich region too long as its trying to richen a lean mixture and "pull" the cycling back to similar time in the rich zone and lean zone.

I'd be looking for a problem causing the vehicle to run lean.

Cheers

Peter Wright

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Steve Pearman User icon on December 12, 2008, 8:20 pm, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"
Steve Pearman

Hi, Last one that i had problems with had the map sensor vac pipe mixed up and connected to to wrong side of the inlet butterfly.

Steve.

Re: Daewoo Matiz 1.0 2004 Lambda question

Posted by Peter Rainsley User icon on December 12, 2008, 11:15 pm, in reply to "Re: Daewoo Matiz 1.0 2004 Lambda question"
Peter Rainsley

Stve,
had this with a Hyundai recently and it was a crack in the exhaust, could not detect the blow, but it made for a similar response to lambda, and took two weeks to kick out a code,
HTH,
Peter

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