While driving my 2010 1.0 107 (same as the Aygo) back from Cardiff a few weeks ago the engine light came on. I've had the car since new, it's done 63,000 miles and regularly serviced by myself, and it's never had a warning light come on in its life. I got it home, plugged in my bluetooth OBD2 reader and it gave me the error code P0420. I cleared it - didn't reset the ECU though - and it stayed off for about a week. Then it came back on. On Friday gone I reset the error code again and drove from Stourbridge to a wedding in Brize Norton, and then from there to Northampton on Saturday morning. On Saturday afternoon I drove a 30 mile round trip from the hotel to another wedding with a mix of A roads and motorways, and the light came back on. Same procedure as before, I reset the code but couldn't reset the ECU due to lack of tools.
I have now had chance to read up on the code, and from what I read it could be down to either the catalytic convertor or the post lamba sensor. At the moment it's difficult for me to do any sort of manual work with the cars as I've torn something in my knee, so any DIY or project I have to do in this time of waiting for MRI scans and operations I need to plan out properly as I don't want to spend forever doing one job only to repeat myself. I know a sensor is fairly cheap and easy to replace, but the cat isn't as easy or as cheap. So I was wondering if there was any way I could test to see if the catalytic convertor itself is collapsed or at fault without having to get under the car, change the sensor, then wait to see if the light comes back on?
For the record the catalytic convertor was changed over a year ago with one from Euro Car Parts. I'm not sure if anyone here as ever seen them, but you buy them and they look like some guy has welded it together in their garage. It has been a bit down on power since then, but before the cat was replaced it was parked for 18 months while I drove a far more powerful car, so I've never been able to work out whether its the car thats down on power or me being unable to tell the difference.
