Scraped through MOT after Uprev

[Zeezeebaba]

Phew

 

After last year's excellent MOT emissions test I was expecting a slight increase this year as I've had the car mapped. Idle CO2 was great at 7% but fast idle scraped through bang on the 20% limit!

Also an advisory on a slightly corroded coil spring but that's good as I can now blag the other half I need to get some new coilovers

[Richf]

Shouldnt make any difference on emissions uprev or not so something else is awry

[Zeezeebaba]

Well it did. Only difference is the fueling is richer and the HFCs are a year older.

It was running to lean before the Uprev so my guess is the increased fuel mix upped the emissions.

[Richf]

Its the HFC's , they need to be really hot to function correctly and even then can barely scrape through. What the fuelling does at WOT on the dyno and what it does closed loop at idle speeds are two different things

[Zeezeebaba]

Not the HFCs mate its the richer mix. Car had HFCS new just before last MOT and I know they need to be hot. Car has done 4k miles since the previous test. Had a service a map and new plugs in between that's all. All lambdas were also replaced last year. I took it out for an hour before the test to get the cats nice and warm

[Floydbax]

I thought UPRev gave a choice of several maps, including an 'Eco' mode. If that's correct then you should have MOT'd it on that map.

[Zeezeebaba]

To be fair it passed so whatever the cause for increased CO2 I'm happy with it Worth the risk for the 25 extra horses after all the mods. I do need to spruce up the underside though as it's looking a bit tired. W brace refurb, new camber arms and some adjustable coilys next.