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MG MGF Technical - Exhaust emissions and K&N filter

Failed MOT fast idle CO 0.57% Limit 0.3%
Advised to have Lambda sensor Cat & ECU checked with main dealer.
They rechecked running engie at 81 degrees fast idle accurately measured at 2577 RPM CO 0.50% fail
Says lamda sensor and ecu ok cannot check cat directly,
BUT did wonder if the K&N air filter might not be helping and suggested refit original filter and re-run emission test.
Does this make sense or should i be grateful the car has done 139000 on origiinal cat?
Autspares group quote
rw cattermole

139000 - I would be more than grateful!

Ted Newman

Unless your K&N is blocked it should help with the MOT test. Seems you may need the new cat, if the senor checks out OK 200-300 ouch, but given your milage not the end of the world.
Think of it as an opportunity to fit a cat and performance exhaust. You may be able to pick a second hand cat up from the MGF breakers in the midlands.If you go for this option make sure its a fairly new undamaged one.Sorry I don't have the tel number to hand.

I got a decent low milage second hand CAT from MGF Centre. Always a bit of a risk getting a secondhand cat but hey, for the amount of money I saved I was willing to take the risk. Certainly 200-300 is outrageous....
tim woolcott

I've recently replaced the cat of my 1997 MGF, at 52000 miles. I knew it was broken inside, but I even found that it was totally empty ! So it would probably have failed the MOT too...

139000 miles on original cat is not bad at all ! and 109 is certainly a very good price. If you fit it yourself, don't forget the 2 gaskets (they are identical) and new bolts (6).


About 140,000 miles is pretty good going for a catalyst - although as Terry says, it may be worth cleaning the K&N filter - and also performing the usual tricks of giving the car a thoroughly good run (full revs, through the gears) to clear any crud that may have accumilated in the cat through slow town driving...
Rob Bell

<<(full revs, through the gears) to clear any crud>>

LOL, Any excuse Rob, any excuse.
paul weatherill

You betcha Paul! ;o) LOL
Rob Bell

This thread was discussed between 24/04/2003 and 25/04/2003

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