new exhaust

[ie Turbo]

Ciao tutti!

I'm installing a new exhaust on my ie Turbo, one without a catalyst. My question is: what to do with the lamda-probe? (i think that's what you call it, it's the sensor on your exhaust right after the turbo).

Thanks in advance!

[Pol]

Keep those Thema's on the road!

I'm not quite sure what you mean:
If you are you using an exhaust, fitted with an oxygen sensor on a car wich normally doesn't have one, then you just leave it there and don't connect it.
In the other case, if you are using an exhaust that doesn't have a connecting hole for the sensor, and the engine has one (a sensor) , I think it's best to try and fit it anyway, the ECU needs to know the amount of oxygen to determine the richness of the gas mixture, otherwise you would have to 'fool' the ECU with a mV signal instead of the sensor.

If this doesn't answer your question, please give more details,

Greetings,

Pol

[ie Turbo]

The old exhaust has a cat, the new one doesn't

My ECU reads the lambda, and adjusts my mixture for optimal use with the cat.
Basically: I wan't my ECU to "know" i don't have a cat, and therefore don't need to use the lambda probe.

I think i have two options:
a) Using an ECU from another thema ie turbo that originally doesn't have a cat
b) Setting up my own ECU so it doesn't use the lambda probe.

The problem is, I don't know how to do either. There should be some jumpers or something i can switch, but i don't know which ones. Can anyone help?

Greets, Sven

ps, I'm having trouble explaining the problem, even to my dutch friends, so I hope this is clear...

[alan cooper]

if you have an engine designed for a cat you should continue to use the lambda sensor even if the cat is removed otherwise it will not run correctly, i am sure that this would be the easiest solution, you will still benefit from any improved airflow through the exhaust system. Are you sure the car will be legal with the cat removed?

[Pol]

In that case, you should keep the sensor and try to fit it in the new exhaust. The ECU doesn't 'know' you have a cat anyway, it just needs to know the amount of oxygen in the exhaust gases to calculate the mixture.
If the exhaust doesn't have a fixing hole for the sensor, you can make one in it yourself.

I don't know if I can help you any further, but you can always mail me (in Dutch) , I think they don't allow dutch messages on the English forum.

Groetjes

Pol

[ie Turbo]

yes im sure, i spoke with the rdw, that's mot in england i think, and they said it's allright, as long as i pass the CO-emissions test. Which shouldn't be a problem.. i hope.
Anyway, there are some tricks to (temporarily) lower your CO-emission.

[Jesús]

I am following this one because I may have a similar problem with my E-class Mercedes. I was under the impression that you need to weaken the mixture anyway since the ECU will assume you still have a CAT and will enrich the mixture to "feed" the catalyst in the CAT. By weakening the mixture you should get lower emissions too. Am I right or wrong here?
Cheers
Jesús

[Rolf R.]

Hi,

as far as I know you`re wrong. Bringing the air/gas mixture to the poorer side will increase emissions due to the fact that parts of the mixture will be unable to ignite and therefore is emitted unburned. That causes a severe increase in HC emissions.

Regards

Rolf