Beitrag #1

I got a high lambda in the TUV.

I tried to test it with a cheap scope and a multi meter.

I videoed it here: https://www.youtube.com/watch?v=VT7Cpy9s4Tg

Do you think it's bad?

Beitrag #2

Das sieht wirklich gut aus.
Wenn du meinst das Umax etwas zu niedrig ist dann liegt das am Innenwiderstand deiner Messgeräte.
Die Spannung der Lambdasonde ist nicht beliebig belastbar.
Die Frequenz sieht auch gut aus.
Alles o.K. in meinen Augen.
Oder was meinst du?
Wenn Lambda am Auspuff zu hoch ist dann liegt das oft an Fremdluft die durch Undichtigkeiten in den Auspuff gesogen wird.
Bei der vehicle inspection Lambda zu hoch ist dann steckt der nette Prüfer zuerst ein Läppchen in den Auspuff.
Wenn das nicht hilft, dann muss man suchen, nur eben nicht bei der Sauerstoffsonde.

Beitrag #3

Thanks. Yes, I thought it's too low. Anyway catalytic converter also looks good by measuring temperatures downstream and upstream. I will try to see if I I can put a rag myself when he tests. And try to search how to check for leaks.

Beitrag #4

Well well, I found a leak between the manifold and exhaust, I don't know why because I put a new gasket there just a year ago when I did an overhaul. I will try to tighten the nuts all the way, because I read in the manual there is a stop in the stud and you should tighten them until you can't anymore, well I don't know what that means, because you can always try more until something breaks, I asked about it the other time here:
https://www.twingotuningforum.de/thread-...pid8772104

Beitrag #5

Bis es nicht mehr geht heißt bis die Muttern satt anliegen und sich nicht mehr von alleine lösen können.
Die Federn übernehmen den Anpressdruck.
Der Feuerring ist je nach Quelle von sehr unterschiedlicher Qualität.
Es gibt weiche mit Drahtnetzstützgitter und sehr harte.
Bei alten Auspuffanlagen dichten die weichen besser, die harten halten länger.

Beitrag #6

Looks like the donut is a little torn where the leak was. I am going to replace the donut. I also tighten the manifold nuts a little more and hope it will help, worst case I'm going to seal it from the outside. I hope there aren't any points in the gasket that leak and I can't see them because of other parts blocking the view.
There is no way I'm going to remove the manifold, there is no access to all the bolts without removing the head.
The gasket was part of the set of Ajusa gasket kit 52105000.
Here is the video of the leaks: https://www.youtube.com/watch?v=pIm8RMj3PnE

Beitrag #7

After replacing the donut, It still has a leak, So I am trying to put the same sealant that i'm going to use for the oil pan - under the donut, Reinzosil, it says it's up to 300 degrees, I hope it will work, at least for now. The manifold gasket seems to seal after I tightened the nut a little more. And I found another seal from near the lambda sensor where there was a welding there. I put Loctite weld on it and I hope it will hold also for now.

Beitrag #8

Measure resistance between lambda housing and battery ground.
100 Hz lambda frequency? Whats that? Measurement error? Its about 1 Hz.
0.4 volts with multimeter is not normal.
There is a joint behind lambda with 2 bolts. Could be corrosive.
Check coolant sensor resistance .
I think, you are a bad influencer on your car.
To open bubbling coolant reservoir to flush electricity is just one of many failures.

Beitrag #9

Hallo ronenfe,
ich stimme da mit cooldriver überein.
Du solltest dein Auto mehr in Ruhe lassen.
Viele Fehler sind einfach nur eingebildet oder Folgefehler deiner Schrauberei.
Fahr das Auto einfach.

Beitrag #10

I would have but it failed the emission test and I need to fix it. By the way, there is still a leak from the donut after putting the sealant. I will put epoxy there too.

I prefer doing mistakes sometimes that cause damage and makes me have to fix more things then do nothing and learn nothing. And I like repairing things.

Beitrag #11

Kunststoffbasierende Kleber halten am Auspuff nicht.
Gungum hält nach eigener Erfahrung, ist aber nicht flexibel.
https://www.holtsauto.com/de/produkte/gun-gum/

Beitrag #12

Went to the tuv again, now it has higher lambda and high co. I think indeed the o2 sensor is bad and got worse, the car is running in open loop that's why it's 0.4 volt. I ordered a new sensor and will update. I think the scope was just showing noise, I am not sure this cheap scope can show low voltage properly.

Beitrag #13

High Lambda = lean.
For sure?

Weiter auf Deutsch.
Das Gerät ist O.K., die Einstellungen nicht richtig.
Input bitte auf DC
Empfindlichkeit 0,2V/div
0V auf auf die unterste Linie legen.
Timebase 1 s/div
Triggerlevel DC 0,4V

Beitrag #14

So my oscilloscope got fried for no apparent reason. Anyway I installed a new lambda sensor and multimeter gives me 1.4 volts now. I hope it doesn't cause the engine to run to rich now. Will go to do a test again on sunday and see.
Maybe I ruined the lambda sensor a year ago when I removed it or cleaned it.
Amplitude is between 0.1 and 0.9 volts, round about 3 hz of frequency.
Anyway, you need to find out frequency and amplitude by using an oscilloscope .
And resistance between lambda housing to battery ground.
Otherwise it is nonsense at all.

Beitrag #15

(11.09.2020 18:13)ronenfe schrieb:  ...Amplitude is between 0.1 and 0.9 volts, round about 3 hz of frequency...

Das ist wirklich gut.
Und zwar sowohl die Spannungswerte und noch mehr die Frequenz.
Alles was größer als 1hz ist ist gut, 2 hz ist sehr gut und 3hz ist exzellent.