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Cats / Emissions 3.0si Coupe

2003 - 2009, roadster, coupe, facelift
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coupedan
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Location: West Berkshire

Cats / Emissions 3.0si Coupe

Post by coupedan » Wed Apr 26, 2017 11:49 am

Bluecat - I am always very sceptical on emission testing equipment. I had a Porsche 996 C4S which failed the emissions test at Halfords. They suggested I take it to a Bosch garage to check which sensors were faulty or not working.
You raise a good point.. maybe I'll go and get it tested again in a few months to see if another garage gives different readings.
Mr Tidy - Wow, this is almost turning into a Montego Blue Coupe thread. :lol:
Never seen so many Montego Coupes in one place! Shame we are not all closer.. could all go for a blast :driving:
Smartbear - Hi, with the mileage on your car this could easily be a sign of a failing ccv system.
Are you burning oil/have sooty tail pipes?
Rob
The car does burn oil but it's not got any worse over the 4 years / 70k miles I have covered in it, I would think that if if the CCV were to fail, I would notice a dramatic difference in the usage of oil? I would say on average (Depending on how I drive it) I burn 1ltr every 2500-3500 miles. which according to BMW is well within "Spec"
andyfanshawe - HI coupedan.
Good to hear your car passed its MOT though.
Regarding the near threshold Lambda reading.

If you genuinely want to find out why the reading was close. and not speculate, find a garage who is conversant with the live data given from the O2 sensors, pre and post CAT. Also with short and long term fuel trims.

Shouldn't be too difficult to assess the performance of the various sensors.

i do an oxygen storage test, that involves sending the mixture rich and looking at how fast the o2 sensors react with an oscilloscope.

More accurately, how long it takes the post CAT sensor to drop lean when the rich mixture is removed, and compare it to the pre CAT sensor. This will accurately determine if any CAT is struggling.

Not cheap, but conclusive.

Alternatively, get a bottle of CATACLEAN and follow the instructions on it. Cost is about £15 and well worth it. Trust me on this.
If you don't believe me, or are skeptical, type in cataclean reviews and prepare to be amazed.

Additionally, make sure the oil and filter are changed regularly and as stated above, any crankcase ventilation systems are clean and clear.

Any slight exhaust leaks will also affect the lambda readings.

Hope all this helps!
An alternative to all this is to enjoy the car and worry about it next year!!

Andy.
Hi Andy,
Thanks for this information! I actually have got some BMW software on my laptop (Inpa, DIS, SSS and so on) I'm not entirely au fait with how to use this, but I am wondering whether I could conclude the live lambda readings myself.. Failing that, then yes, it is a good shout to get a garage to do it.

I shall have a look into this CATACLEAN - how does it work exactly, is it a fuel additive or something like the "Terraclean" things where they pump it around the engine to clean carbon build up?

I shouldn't have any exhaust leaks, I recently had the connection from the downpipe to midsection corrode but this has now been fixed and there were no further leaks.

Cheers.
Dan.
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andyfanshawe
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Cats / Emissions 3.0si Coupe

Post by andyfanshawe » Sun Apr 30, 2017 2:04 am

cataclean is a fuel tank additive and is amazing stuff. Saved many of my customers a big cat purchase. Including my z4 cat!

https://www.cataclean.com/

I have INPA but, like you, havent used it much. I use snapon verus to watch the o2 sensors in action.

The lambda reading is a calculation based on the emissions. Yours is still good. If you have it checked again, make a note of the CO, HC and, if you can, the oxygen content. NOx readings also if you can find a machine to do it!

Put that CATACLEAN in!!
Andy.

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