I had a similar issue although I'm not sure if it's exactly the same, but the info in this post might help:
My CO was only 0.6 so not nearly as high as yours
ok, so I now have not p0420 fault code :racer:
Iit looks like it was the CATs, i got a guy to have a proper read of all the sensors and confirm that there was nothing else that he could see that could be causing it and also that there was nothing else that would damage the new cats.
then i just...
yeah unfortunately my brain wont let me just code it out. :disrelieved:
It doesnt really matter if the fault code is coming back or not, the CO levels at an emissions check are still too high, 0.6 rather than below 0.3
There is something wrong with the car, just need to find out what it is.
Time for a wee update,
So, I took the car to Bradbury Motor Group in Prestonpans to get the injectors serviced as part of my investigation into why the fuel economy had dropped a lot, they came back and said two of the injectors would only just pass and two of them were screwed and letting in a...
Thanks again guys,
I logged those blocks out to a csv and had a look and i think it all seems normal, I've put a link to the csv file if anyone fancies a look, also if anyone fancies explaining it a wee bit, it would help me and might help others too :-)...
Thanks guys, that's very interesting information. i didnt think of searching youtube, it ended up being a late night on youtube last night :)
My car has one pre and one post cat sensor. I hope they're not 200 cel cats, I'm betting it's sods law it wont say on the cats the model number.
ok, another update :sob:
when driving with my brand new MOT and a smile on my face the 30 miles back to the garage to pick up the car i had borrowed from my old man the ****** engine light came on.
When i got home (after swearing a lot) i scanned it with VCDS and it was the same fault as before...
Thanks for your help guys, it has now passed it's MOT.
The garage doing the work replaced both Lamdas and then took it to their local test centre and it passed.
I went and picked the car up and took it to my local garage to get it's MOT retest done, it passed there too although they did say it...
Sorry in advance for the long post. I'm having an issue with my 2001 S3 AMK, it failed it's MOT on emissions saying the CO levels were too high. Also my MPG had dropped from 27 to 24mpg at the same time the fault appeared:
Fast Idle Test:
CO - limit 0.3 - actual 0.77 (FAIL)
I had the same issue that my 2nd to 3rd gear change crunched but mine was only once the gearbox had warmed up (it was fine when cold)
I tried the following (this is just what i tried and worked for me):
1. adjusted the gear linkage (no difference)
2. replaced the dogbone bush with a red...