k11 1.4 Coil pack Lambda sensor

[twodogs]

Hi people. I'm after a lambda sensor for a k11 1.4 coil pack model. I keep getting the bank 1 too lean error. I've replaced the maf and am still getting the error. (Hope the maf from amazon is working). Thank you.

 

[frank]

i probably have a 4 wire one twodogs, you,re best to test your ones first tho really (voltage reading when warm)

 

[twodogs]

Thanks for the advice. Which wires do I take the voltage across.

 

[frank]

Thanks for the advice. Which wires do I take the voltage across.

the black one iirc mate, and any earth point
and i think the 2nd lambda should have a similar reading to the 1st one, albeit slower

 

[twodogs]

Ok Cheers frank I'll dig out my multi meter this week and give it a go.

 

[twodogs]

Frank, if you do have a lambda could you please let me know. Swapped out the maf for a known working one. Checked the o2 sensor voltage on the Torque app the first one spends alot of time jumping around even at stable revs. It regular shows a lot lower value than the second. So I belive that means it is reading leaner. Damn light still coming on.

 

[frank]

Frank, if you do have a lambda could you please let me know. Swapped out the maf for a known working one. Checked the o2 sensor voltage on the Torque app the first one spends alot of time jumping around even at stable revs. It regular shows a lot lower value than the second. So I belive that means it is reading leaner. Damn light still coming on.

i have about 10 x 3 wire ones and 1 x 4 wire one mate and the 2nd lambda should basically mirror the 1st one (but more slowly)

 

[twodogs]

The second one doesn't mirror the first. It does sometimes but the first reads closer to 0 a lot more. The second tend to be between 0.5 and 0.8 where as the first goes from 0.1 to 0.8.

How much would you want for the 4 wire one ?

 

[frank]

does,nt sound too bad, have you tried swapping them ? and £5 + post ?

 

[twodogs]

No I haven't, are they both the same ?

For that price I'll take it. Would you take PayPal ?

 

[frank]

are they both the same ?

hopefully they are because mine is a 1st lambda

 

[twodogs]

This car is driving me crazy. Fitted the new 1st lambda, and got a noticable difference in smoothness and power delivery. 200 miles later the light came back on. Reset it, disconnected the battery and now it's only doing 50 miles before the light.

ive changed maf and 1st lambda for known working ones so the problem isn't with them.

Got a good second hand cat coming, I guess it could be post cat lambda also.

 

[twodogs]

Wanted good second lambda if any one has one please.

 

[frank]

sounds like a longterm fueltrim issue to me gary, have you checked for faultcodes ?

 

[twodogs]

The only fault code that keeps coming up is p0171

 

[frank]

The only fault code that keeps coming up is p0171

a bluetooth dongle thingy and torque app will monitor the short and longterm fueltrims i think mate https://www.micra.org.uk/threads/k11-1-4-cga3de-p0171.63352/#post-714054

 

[twodogs]

I've just got one of those that's how I'm reading and resetting the code. What sort of values do I need to be looking for and what range should they be? Any ideas. I'll try to get a pic of one of the screen shots from it yesterday.

 

[frank]

basically the fueltrim adds or subtracts fuel (injector duration) to the self-learn map, but if the maf is faulty the ecu has to add (for p0171 lean) extra fuel, and if this exceeds a certain percentage it flags the light

 

[twodogs]

 

[twodogs]

 

[frank]

dunno if that 99.2% fueltrim is relevant ?
the maf readings @ idle should tell you if its an inlet leak or not, my money would be on the maf tbh

 

[twodogs]

Do you know what the maf at idle should be ?

 

[frank]

Do you know what the maf at idle should be ?

fraid not an airleak would be worse with the throttle shut (high vacuum idle) so the maf wont be seeing that air intake, and wont sense/register it
i think the short term trim would be adding fuel, then when you open the throttle to reduce the vacuum, it would have to pull back again (a minus figure)

 

[twodogs]

I'll get hold of some easy start to spray round to check for an inlet leak.

It's a pain if it is the maf as I've tried an amazon one and a known working one.

 

[frank]

I'll get hold of some easy start to spray round to check for an inlet leak.

It's a pain if it is the maf as I've tried an amazon one and a known working one.

if the short term trim is stable as you open the throttle i doubt if its a vacuum leak gary,
the 1st lambda looks to be bouncing around .4v ok, and the 2nd looks stable at .5v (i would have expected a lower value tho ?)
i would check the 2 lambda,s out on the road personally
the maf readings should be a steady rise as you load the engine (in gear)

 

[twodogs]

I'll take the car out for a drive later and video the results.

 

[frank]

I'll take the car out for a drive later and video the results.

and see if you can do an ecu reset to zero the fueltrims, then monitor them eh

 

[twodogs]

any ideas on how to reser the ecu ?

 

[twodogs]

Do you just mean cancel the codes ?

 

[frank]

any ideas on how to reser the ecu ?

disconnect the battery and earth the + lead usually

 

[twodogs]

Have rest the ecu. It was really lumpy to start with but things have smoothed out. I now have my video of my drive to work with sensor readings. I'll try to post it up tonight. Someone might understand what is going on better than me. I'm just looking at numbers.

 

[twodogs]

Just as a finisher to this thread. After staring right at the beginning of the system and swapping out
Plugs
Air filter
Maf sensor
1st lambda sensor
Cat

It turned out to be none of these.

It was the second lambda sensor that was buggered.

Apart from the filter and plugs all other parts were used so all in all still less than a new no2 sensor