Looking for a bit of advice please. My SE failed the MOT with an emissions issue, it's blowing a CO reading of 5.3%. I've got it booked in with Williams Automobiles in Chipping Sodbury (seems to be the closest Lotus specialists), but they're not confident working on M100's as they don't get many through and apparently Lotus themselves aren't much help. They are however willing to have a look which is infinitely better than most of the garages I've spoken to so far.
As such I'm looking to provide them some suggestions to to try to help things along. My mechanical knowledge is pretty much 0, though owning a Lotus it seems to be increasing surprisingly rapidly... I don't necessarily have to do all of these, so I'd like to know how effective each is likely to be:
- I understand there's meant to be a CO pot somewhere that can be adjusted (anyone able to point me to where and how much adjustment it can take?)
New air filters sound like a good idea, are these inside the trashcan? Also is the following a drop in part or is this part for an open filter conversion - here
ECU change - I understand Lotus released a new ECU that lowered emissions, my concern is that Williams won't have the equipment to read which PROM id my current ECU has to know whether to do this. If I did go this route I was thinking of going for a Mountain chip (which I understand features the same reduction) as it's probably easier to get than the stock Lotus ECU
Dump valve - I've seen some places suggesting that a dump valve improves emissions... is this true? Best guess as to why is simply that it vents those gases into the engine compartment rather than out of the exhaust, can anyone enlighten me on this point?
Fitting an O2 sensor and going closed loop, seems drastic and there's a bit of debate as to whether this approach is worth it from what I've seen. What's involved in this aside from the O2 probe and an ECU that understands it?
Any and all suggestions welcome.
Many thanks
Edward