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Discussion Starter · #1 ·
Hi,

Has anyone had any failed MOT's with a Mini Mania manifold & cat due to emissions? - or can anyone suggest other likely causes (as this is yet to be proven, it’s just one thing that I can think of at the moment whilst I’m waiting for the car to be checked into a garage).

Car setup..

MCS 52 plate
Alta air intake
15% reduced pulley wheel
Iridium plugs
Minimania manifold and cat

Failed the MOT today on fast idle test (twice - first @ 0.473%, second @ 0.288%). A pass is <= 0.2%,

It’s had new oil, oil filter and plugs (about 8k ago) but it hasn’t been re-serviced yet (which could be the answer to my question?!). I need to clean the Alta air intake as its a bit oily.

Would an ECU re-map help? - A bit clueless here so any help would be appreciated.

Is it advisable to take it to a mini service centre with these mods or is there anywhere else near London which anyone can recommend?

Cheers
 

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if its not the CAT itself then its probably a faulty o2/lambda sensor... Dont think an ECU remap would help.

The exhaust gas oxygen sensor (EGO or O2), or lambda sensor, is the key sensor in the engine fuel control feedback loop. The computer uses the O2 sensor’s input to balance the fuel mixture, leaning the mixture when the sensor reads rich and enriching the mixture when the sensor reads lean.

A lambda sensor’s normal life span is 30,000 to 50,000 miles. But the sensor may fail prematurely if it becomes clogged with carbon, or is contaminated by lead from leaded petrol or silicone from an antifreeze leak or from silicone sealer.

As the sensor ages, it becomes sluggish. Eventually it produces an unchanging signal or no signal at all. When this happens, the Check Engine Light may come on, and the engine may experience drivability problems caused by an overly rich fuel condition. Poor fuel economy, elevated CO and HC emissions, poor idle, and/or hesitation during acceleration are typical complaints.
 

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It's more than likely a poor quality catalyst. many aftermarket cats are made of inferior quality,and will not reduce emissions enough to pass an MOT.
I've lost count of the amount replacement cats I've got from motor factors that have had to be replaced with genuine ones.
this is very common on peugeots and rovers, and usually brings the engine MIL on, and a trouble code for an 'ageing catalyst.' when a genuine part is fitted,problem is eliminated.
 

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Discussion Starter · #4 ·
cheers... going to get it booked in with Mini asap. I'm hoping it'll be the sensor as i'd rather not have to fork out loads for yet another manifold and cat less than 12 months after buying the last one!!
 

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If its been less than 12 months you may be able to get a replacement CAT if it turns round to be that, the one you purchased may have come with a 12 months garantee... Check it out.
 

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Turbo Schmurbo...
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No emission problems on my recent MOT, running Janspeed Manifold , JCW cat back, 15% Pulley, 380 injectors, gp intercooler, Jcw/m cai and standard ecu from a facelift MCS.

I found the pre-facelift ECU ran the mixture very, very rich with a 15% pulley. Pop into your dealer and ask for an ECU update they charged me the minimum labor charge (15min job).
 

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Discussion Starter · #7 ·
Thought I’d provide an update…

As it turns out it was a faulty catalytic converter. The company I purchased it from has given me a full refund but unfortunately I couldn’t wait any longer, so I had to shell out nearly a grand fixing the problem with the Mini dealership. Not good.

A lesson learned.
 
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