8 replies to this topic

[Hodgheg]

Hi I'm new here, got a 1996 SPI (it's an 'Equinox' actually) with very low mileage and a perfectly sound engine but for the fact that I was persuaded to get a sports exhaust for it and ever since it's been failing mots on emissions of (I think) nitrous oxide. And not just a little over, it's off the scale.

 

I've changed the lambda sensor in the exhaust and thought it smelt a bit better but wishful thinking apparently, it still won't get a ticket. I'm assuming that the exhaust is the problem, wondering if I should fit a standard exhaust or if it's possible to tweak the ECU somehow, or if another sensor might be to blame? The spark plugs are a delicate shade of light brown so the mixture itself seems OK.

 

All advice appreciated including suggestions on where to take it if necessary; I'm in Manchester but prepared to travel if there's a really clued up specialist somewhere??

 

Cheers, Richard.

 

 

 

 

[MatthewsDad]

I don't think the exhaust is the source of your problem, unless someone has removed the cat? You won't be able to tweak the ecu. My first step would be to download the rover mems app onto your phone and connect it to a diagnostic cable (available on ebay). Otherwise you're chasing the problem without data. Also check the vacuum hoses, fuel trap etc. There are plenty of helpful posts on the forum covering this, and more knowledgeable folk than me who can decipher the data from the mems app.

[madazv8]

Does the car idle correctly and smoothly or run obviously rich? (black soot comes out exhaust)

If it does idle nicely, then a lot of the usual suspect areas can probably be narrowed down. 

[sonscar]

Long time memory but is nox affected by ignition timing,Steve..

[viz139]

When you changed the exhaust did you change the exhaust manifold? If so where is the lambda sensor located?  Double check all your vacuum pipes.

[68+86auto]

Long time memory but is nox affected by ignition timing,Steve..

Apparently yes.https://www.crypton.... emissions.html

 Screenshot_20240506_103605_Opera.jpg   43.68K   1 downloads

[68+86auto]

Have a read of this: https://www.crypton....ssions/NOx.html

[Hodgheg]

Thanks for all your help, all the pipes, fuel trap etc are new, the lamda sensor too, which is located where the manifold meets the single exhaust pipe. I think what I need is a genuine expert but the Mini specialist nearest to me is suspect and I don't know any others. I'm in the north west of England and prepared to travel to get this put right. Any suggestions for decent garages much appreciated.

[MatthewsDad]

You have AB Garage at the opposite end of the M56 - give Adrian a call and see whether he can help. He works on injection as well as carb set ups.