ECU considerations

[230ceBruno]

I am looking at getting another w124 coupe and I though is it possible to it and ECU from a catalyst equiped vehicle just jus add the oxygen sensor and ignore adding the catalyst?

If it is what are the potential effects?

 

[eric242340]

I am looking at getting another w124 coupe and I though is it possible to it and ECU from a catalyst equiped vehicle just jus add the oxygen sensor and ignore adding the catalyst?

If it is what are the potential effects?

Errm, could you explain this a little better. o2 sensors wihout a cat will give the wrong readings.?

 

[television]

Many people have removed the CATs and no malfunctions recorded and even passed the MOT. My 129 passed without cats though I did fit then when I sold it. There are 2 places where the O2 sensors on MBs on the exhaust manifold and in the down pipe, some have both. One of the purposes of the O2 sensor is to protect the CAT.

Malcolm

 

[230ceBruno]

Errm, could you explain this a little better. o2 sensors wihout a cat will give the wrong readings.?

I literally mean what I said, I theorise that the presence of the sensor sending messages to the ECU might result in more efficient running than without.

My assumption is that the cat is there to process whatever passes thru it without intervention from any other part.

 

[rio678]

Without the cat will give a fair bit more BHP.

 

[230ceBruno]

Without the cat will give a fair bit more BHP.

Okay?, but are you also saying it is possible to swap the ECUs (a without cat one to a with cat one)?

 

[230ceBruno]

When I swap the ECUs, is adding the O2 sensor (thats the lambda right?) a straight forward plugin thing? and where/how does it plugin?

 

[television]

When I swap the ECUs, is adding the O2 sensor (thats the lambda right?) a straight forward plugin thing? and where/how does it plugin?

You do need a hole for it in the exhaust manifold, it will be a threaded hole.

 

[230ceBruno]

Clarification: PLS Read all who have commented previously

Sorry for the typo in my original message. I meant the w124 I am looking at is a non cat vehicle. I have access to the +cat ECU(fairly used) and the accopanying lambda sensor (brand new) and I wondered if the combination will work in the car.

Well, hoping to get the benefits of the later model ECU and adding the sensor to make sure the ECU gets the readings it expects. Pls comine this msg with my plugin message earlier

 

[television]

Well if you can get it to work, it should improve the running efficiency of the car as when the O2 sensor came along ,this was the start of cleaner engines.

 

[230ceBruno]

There is wha looks like a threaded hole in the exhaust manifold of this non cat car but looking at the pics of the sensor I dont think it is big enough.

Can any one tell me if I can diy the fitting and how?

 

[230ceBruno]

A new thought

Is the connector i.e. harness to ECU connector the same? as in the not cat car. Pls replies are needed soon as I need to decide as the sensor (brand new) and Ecu are going for quite cheap but wont be held for me forever.

 

[type49]

Difficult one. The later control units for 124s were chassis coded after 30 starts. I pressume you have a problem with the ECU or wiring on your own non cat car, is that correct. What car & year is it? I know some people remove the cat but I would have thought you would still need the lamba sensor to tell the ECU what to do. Basically, the sensor measures mixture but it's actually quite crude. All it does is tells the ECU that it's too weak-richen the mixture, now it's too rich-weaken it off etc etc, a few times per second. It does have a heating element but that's a separate issue. This should give an avarage lamba reading of "1". Check your MOT, it will be between 0.96-1.04 if you have a cat. Unfortunately, I can't answer your question without knowing all the facts & also having previous experience of doing the job. In theory it should be possible but wether it will be easy, I don't know. :-|

 

[230ceBruno]

From square 1;
I have discovered a timewarp 300ce 88, I have access to a cat ECU with brand new lambda sensor.

IF I can be certain that the interface with the car's connector and; the from 89 on + cat, ECU then I can go ahead and and procure it and install.

This is the information I need

 

[kth286]

Bruno

The depth of detail about the electronics inside an ECU is just not readily available and so it is not possible to say if they were compatible.

I just would not do it - cars are complicated enough as it is - why make your life more so.

Change the car for a later model perhaps.