S1 Exige emissions

[kerryxeg]

MOT day for the exige today and it's went well until he stuck a pipe up the exhaust. It's basically running very rich. It now has the 190ecu (pretty sure that was changed after last years MOT). Ricky did it so not sure if I could simply swap back to the 177 if that was the issue (I'm not 100% sure it has ever run correctly with the 190 ECU - clearly using more fuel with it). I did have an exhaust weld go last year, which may have sooted up the Lambda sensor - so that's the first thing I'm checking if I can get it off. I'll check the plugs just in case, but it's actually running well.

Any other words of wisdom?
If the ECU simply an unplug exercise?

The MOT tester in Kemnay will give me a few minutes to check it tomorrow morning if I can get it sorted, but don't want to go back and bother him unless there is an obvious improvement.

Kerry

[robin]

Not much I can say other than Lambda loop must not be working properly; it should always pass if the lambda sensor works and the catalytic converter is fitted, I think.

[philthy]

Mine failed emissions with the CAT in place as well. I think the mapping of the 190/177 is a bit hit or miss since they were just plug and play affairs onto engines which were very different from each other, probably why so many convert to emerald.

[kerryxeg]

Ok thanks chaps, I'll check the sensor - I have had to clean it in the past so maybe the same problem again.

I actually have an emerald in the cupboard, just need an educated person to help with inspirational fitting and some spare time.

Kerry

[H8OAG]

I had a failure reading on my S1 which marginally passed on a second attempt........after a short break for a quick roasting along the Crieff - Perth Rd.
There was no visible difference in the reading when swapping 177 and 190 ECU's.

[steviej]

A good 'spirited' run for a few miles to heat the cat up, followed by a mile or so at high revs with light throttle, then straight onto the emissions machine if posssible sometimes does the trick if the garage will allow you the time

[Corranga]

Yeah as others have said, get the cat / exhaust nice and hot then try again. My s1 Elise has a similar issue each year.

[kerryxeg]

Thanks folks, it actually had a good roasting last night and again this morning for this very reason. I'm pretty sure it'll be the Lambda sensor, which I've given up trying to get out.
I just don't have the time to mess with this just now and there are a couple of issues which need sorting, so spoken to Ricky and he'll sort it out for me next week, what a star.

So new sensor coming just in case and I'll get the bypass thermostat changed at the same time.

Good info on the 190vs 177, it may be that the low temp thermostat was just more of an issue with the 190 than the 177 and so it's never been quite right with the 190 ecu. Other than the emissions it is actually running great, but I did notice a good thirst for the fuel - probably 50% going out the exhaust.

Kerry

[Dave]

Dont forget. with the 190 upgrade one of the cam pulleys was also changed, not sure if it was the inlet or the exhaust, so it's not just a case of swapping 177 and 190 ECU's.

Dave

[Gourlay83]

Plug it into an OBD reader and make sure your ECU is switching to Closed Loop, and check your lambda readings. Should be fluctuating from 0v - 1v, with .5v being 14.7:1 AFR ( i think ??).

Alan

[jj]

Pretty sure none of the S1 exiges have OBD-tech? Certainly neither of ours did.

[kerryxeg]

Thanks folks, yes the cam pulleys were changed TBH I didn't remember so the thought of swapping the ECU back would obviously be a more complex job. I doubt that's the problem anyway, pretty sure it'll be the Lambda knackered or sooted with the root cause being the low temp thermostat and too much rich running trying to warm up. Anyway it's gone to the pro. But thanks for the comments, they helped confirm the likely issue even if it mean't I wasn't going to sort it out.

Kerry