MOT failure - emmisions

[Ganglandboss]

I have a '99 S1 Elise. It is the 118 BHP model. It is standard other than a Hurricane induction system, Magnex exhaust, Eliseparts high flow sports cat, Eliseparts flexi section and some non engine related mods.

It failed it's MOT a couple of years back on emissions. I discovered the centre section was blowing, so I replaced it. I was advised to check the engine mounts and exhaust mounts, as they are probably at the end of their life. I found they were, so I replaced them.

When I was ready for an MOT, I took it to a garage where a mate of a mate worked. They told me it had failed because they couldn't complete the emissions test, as it had thrown the contents of the coolant system out.

I got it home, but due to other commitments, I have had no time to sort it. I did check for leaks though, and I found diddly squat wrong with it. It developed a really bad exhaust blow shortly afterwards.

My suspicion was that it was blowing from the flange between the manifold and enter pipe, but I was unable to get it in the air.

Now I have some spare time, I managed to get it on ramps and checked. The flange was fine, but I did discover a blanking plug in the centre section was missing. Eliseparts told me there was an error when the centre sections were manufactured. Apparently the Lambda sensor is on the centre section on the Toyota engined cars, and their manufacturer misinterpreted a drawing. They sorted this by fitting a plug. I have no idea how it came out; I can only suspect it vibrated out.

I decided it was also worth checking the lambda sensor and it fell apart in my hand. One new sensor and a blanking plug later and she's purring.

I took it for an MOT today and it has failed in emissions. It is okay on natural idle, but well over on fast idle.



Since changing the Lambda sensor, it has only run at idle and had a short run to the garage. They said an Italian tune up may be the answer. I will give this a try, but I was wondering if there is anything else I could check. Any advise would be appreciated.

Edited by Ganglandboss on Tuesday 7th July 19:52

[Tickle]

You say your mate works at the MOT garage. Does he like beer? Sometimes this helps cars with de-cats pass MOTS, may be worth a try

[Ganglandboss]

Tickle said:

You say your mate works at the MOT garage. Does he like beer? Sometimes this helps cars with de-cats pass MOTS, may be worth a try

He's left and gone working on trucks. His boss tested it last time and I don't want to take it back there. The coolant issue makes no sense, which makes me think he was meddling.

[Ganglandboss]

It's passed! I also posted in the engine and drive train forum and got some good advice. Somebody also pointed out the hydrocarbons were high, and it would be worth checking the ignition. I've changed the plugs, dizzy cap and rotor arm, and thrown a new set of leads at it. I'm not sure the leads were part of the problem, but one in particular was looking past its best. As many will be aware, rainwater can get into the spark plug ports and there was signs of rust deposits on the shroud and corrosion on the connector.

Between the above and an Italian tune-up, I have got the emissions down, but the CO is bang on the limit, so I'm worried I may have a problem next year. I'm going to get it checked again after using it on the road again, but I'm wondering if it would be worth taking it to a Lotus dealer for a diagnostic check? Am I correct in saying the S1 models won't work with a generic code reader? I understand a European law requires a common protocol, but I believe that only affects later Toyota engined models.