I've heard from a good source that if you do a full decat on the STi 7 then a permanent code is written to the ECU.

If this code is noticed then your warrenty could be voided.

It must be something to do with the Lamda sensors so the centre section cat would be safe to remove, especially as it is liekly to go with the PPP.

I just thought I would mention it as I couldn't see a thread about this before.

Mark

Interesting. I wonder if Stephen Done could comment?

Cheers,

Matt :)

Interesting. The question is can the STi ECU write trouble codes that cannot later be erased. And then cannot is relative - is it locked in software and written to Flash or EEPROM, or is a genuine write once area. Not seen anything on Delta Dash about this which tends to display everything the select monitor does and more. How could the code be specific to a decat rather than just the catalyst inefficiency code?

I agree John... sounds like it is most likely the 0420 CEL indication.

As mentioned in other threads, this is quite easily resolved either via Scoobysport, or also potentially using an O2 sensor simulator.

More info. on this in the i-club BBS in the US:

www.i-club.com

BTW the big pipe might be more of a giveaway than the code in the ECU? :)

You can always change the pipes back though can't you! If the ECU do make a permentant record then you have more of an issue.

I was just saying what I have been told and I do trust this source. Sorry for trying to be helpful!:rolleyes:

I think that's likely to be scaremongering, though I wouldn't guarantee it.

ECUs don't generally have the facility to reprogram themselves, since this is risky. By the nature of flash memory, you erase and program in blocks, not individual bytes. The ECU will not be able to do this while running. Having said that, the ECU must have other writeable memory to set the immobiliser code, so it is possible.

See if you can find a someone who has been told this.
Find out how you view the message, if it exists.
I.e. Is it via select monitor. If so, what key presses ?

You do get a trouble code when changing exhaust. I think it's one of the lambda sensors or a hot cat light. But that's just a trouble code that you can reset. It may appear to be permananent because it comes back every time you clear it, until you remove the exhaust.

Steve