Engine management light....deficient cat!

[grdunn123]

Driving to work the other day and the management light came on.....got the code read and was told that it was a deficient cat. Garage reckoned a new cat was £800 + fitting! Suggested and tried using Forte fuel treatment to clear any crap and reset the fault code.

Light has stayed off so far but what are my options should it come back on?? Checked Ebay and cats are available for my D2 4.8QS at about £250 ish for the parts......what about a de cat exhaust system???

Any ideas would be welcome

[sutherland]

I'd recommend a couple of 200 cpsi sports cats and if your car has post cat probes (sounds like it does) the angle block connectors that remove the probes from the flow. I got two cats fitted for £400 and the angle blocks were about £60.

Works perfectly.

[Andy_Bangle]

If the light has stayed off then it sounds like the cat is ok, it just could have been a bad batch of fuel or air in fuel system. What was the error code - P0420? (Catalyst System Efficiency Below Threshold). If it was this can come on for a number of reasons, either from a signal from the pre -cat O2 sensor OR the post cat O2 sensor. Often the signal is from the Pre-cat sensor, and although putting the light on (symbol of an engine on the Mini), usually no fault code will be present. It will remain on for a number of drive cycles (usually 2 or 3 days) even if the the over rich mixture is not detected again within that period.

Also using 95 Ron fuel and /or giving it beans whilst still warming up, will make the light more likely to come on. Remember It is only a 'flag'. Its not reducing power or changing the way the car performs.

As my JCW is slightly modified the light is always on since replacing the Manifold & Cat so i'll be looking at either removing the O2 sensor or using an 'angle block' - 20 quid in my case.

Edit: BTW, did the garage do an emission test? as that's the only way to see if a CAT has actually failed

Edited July 24, 2009 by Andy_Bangle

[grdunn123]

I have very recently gone back to using superunleaded after maybe a year or so on the supermarket cheap stuff. The garage didn't do an emmissions test, just read the fault code. Not sure what it was other than what was written on the invoice.' cat convertor inefficeint, advise Forte fuel treatment'.

Haven't driven the car much since this but light has stayed off.

Worth sticking to superunleaded fuel or not?

[Andy_Bangle]

Strange that the garage can say that the cat is gone without testing it, never mind give me 800 quid and i'll fix it for you :D

I reckon it was that the pre & post sensors where detecting a 'to small' difference between them. Super should help. Hopefully the light will stay off. Check that your petrol and oil filler caps are on correctly and your airbox is clean.

Edited July 24, 2009 by Andy_Bangle