ecu swap
 

A few months ago I remapped the ecu and now car wont pass emissions test. I did it at a garage when I was abroad with the car,so its not so easy to go back there! So I was wondering if I can buy a second hand ecu to put in just for the test. Excuse my ignorance, but is it just a simple process, a case of just swapping the ecu in the trunk,or will I also need to change the immobiliser and keyfob? I was hoping that as long as the part numbers of the ecu match,ill just have to swap the ecu. Any suggestions please?

No, it is not a simple swap. The system will need to be coded to work together, and depending upon the year of the vehicle, will require either a PST II or a PIWIS system. The DME will also have to be correct for the year, model, and how the car is equipped.

My car is a base 1999 model. I found an ecu from a 1999 box complete with immobiliser and key fob. So that would still not be enough,it will require some coding as well?

Go to a porsche dealer and ask for an ECU programming, that will replace the tuned map with the original one.

Yep, I think that's the easiest way out. I thought maybe I could just buy a second hand ecu and put it in just for the emissions test,and then swap it again,but I don't think its viable that way!

Or you can get a galetto FGTECH V54 and switch the files when you need via the OBD socket
I used to do it, very easy, only 5 minutes, nothing to open

Problem is dont have the original map! Is there anything I could do to "cheat" the test? Its failing on co emissions they should be at around 0.5% and theyre reading about 2%. Is there anything I could temporary do to reduce co emissions for the test?

This solution will work fine! No additional coding is needed and no visit to the dealer.

You will also have to swap the key shank from your current key to the replacement key so it releases the steering lock (very easy to do in a couple of minutes). Be careful not to lose the little transmitter "pills" inside the key fobs!

Having two sets of fob/immob/ECU will also let you easily swap back to the modified ECU/immob/fob after passing emissions testing (if desired).

Really? Wow thats what I want to hear. I found a second hand ecu together with immobiliser and key fob. Would I need to change those three for the car to work well? I will just need it temporarily till I do the test.

If you do not have the original, you can read the file BEFORE you go to the dealer, update it at the dealer,
go throught the co emissions control, read and save again the original and write the tuned one.
You will have both at your disposal, it is the cheapest way.

If you put another ECU, the number of hours will not match the cluster if you want to sell it.

Yes, the ECU/immob/fob are programmed as a matched set, so you will have to swap all three for the car to run. This should let you pass the emissions test and then you can swap back to the modified ECU/immob/fob set. Just keep the second (stock) set for emissions testing.

I know this works because this is exactly what I do.

Problem is I'm not too technical,I dont know how to write maps and stuff like that. I like your idea,but it might be a bit out of my reach!

Cool, glad to know I'm not the only one thinking about this�� I think ill buy the set and see how it goes