Honda have now put a 3rd o2 sensor into the car and have also replaced the ECU with an ECU of a car the same age which turns the CEL light off. This apparently means that I need a new ECU asap or else damage to the catalytic converter could occur. Honda have said that it would cost

 

I'm not qualified to diagnose if that's the actual cause of your problem, and there isn't really enough info to accurately do so over the internet, but if that is what's wrong then that seems insanely expensive for an ECU. For that cost I'd be all over a stand-alone management system, AEM EMS for example.

Or go rip one out of a wrecked S, which I know there have been many of since 2001 in the UK, and get it reprogrammed at the dealer to match the chip in your key.

 

My dad had to have the ECU replaced in his Insight due to similar symptoms, IIRC. However, just because the dealer dropped a different ECU into your car and it didn't throw a code, that doesn't mean that the ECU is definitely your problem. How long did they leave the ECU in the car? What type of driving did they do with it in?

As mentioned, if you get an OEM ECU, I'd look for a used 02-03 ECU. There are probably some in scrap yards or on eBay (from people that have switched to aftermarket).

But, for 1100 pounds, you could get something more flexible that OEM (if you don't have any emissions laws or whatever that restrict you).

 

Agreed, regardless of what you do here, EMS or stock ECU, don't replace with the 2001 ECU when you can just as easily upgrade to the remapped 02-03. Don't let them tell you they can't do it either, it hooks up exactly the same and the only difference is the fuel maps.

You're making a step up regardless so at least that might help soften the blow a little

 

https://www.s2ki.com/forums/index.php?showtopic=502879
In your other thread on the same subject you mention you recently had a clutch replaced. I hope those who have diagnosed a faulty ECU took the time to check to see if any of the wiring was damaged. It also looks like whoever is quoting you prices is using the U.S. dollar prices and charging you in English Pounds. You said they wanted 220 Pounds for something that costs $220 here in the states. Again they qouted you 1100 pounds for a new ECU. I think a new ECU runs around between $500 and $700 in the U.S. This is a Honda dealer right?

Just checked, something that costs $700.00 US should be 347.33 English pounds. So all the prices they have qouted you seem almost absurd.

EDIT: 1100 pounds = $2218.48, you could buy a Mugen ECU for that much if i'm not mistaken.

EDIT AGAIN: It appears you could have any ECU you want for the price they want to charge you.
Honda OEM MY03 $550-$700
Mugen N1 = $1628.00
Spoon Sports Computer $1300.00
AEM Full EMS $2724.75
OK the AEM EMS is higher, but it's closer to what they are trying to charge you than the stock ECU.

 

AEM should be in the $1500 range.. unless you're adding on UEGO controllers, guages, etc.

 

IF YOU ARE GONNA PAY THAT MUCH FOR AN OEM, YOU MAY AS WELL GO WITH THE AFTERMARKET THATS OLD NEWS, NEVER PAY ALOT FOR OEM PARTS..............

 

I have a 2003 oem ecu with less than 3000 miles on it. If your interested PM me we can work out a price.