26-08-2014, 08:37 AM
(This post was last modified: 26-08-2014, 08:37 AM by powerandtorque.)
Yup, I'd go with the cat having failed, probably due to the unburnt fuel from the suspect failing coil(s).
You'll usually get something in the region of 0.5% CO with a good lambda but failed cat, which is roughly what you've got.
Fit another known good cat for the MOT and I'd expect the emissions to drop right down, but unless you fix the misfire that's going to be resulting in unburnt fuel going down the exhaust you will kill the replacement cat.
Aftermarket pattern cats are rubbish btw - it'll probably get you through the MOT, but don't expect it to last.
You'll usually get something in the region of 0.5% CO with a good lambda but failed cat, which is roughly what you've got.
Fit another known good cat for the MOT and I'd expect the emissions to drop right down, but unless you fix the misfire that's going to be resulting in unburnt fuel going down the exhaust you will kill the replacement cat.
Aftermarket pattern cats are rubbish btw - it'll probably get you through the MOT, but don't expect it to last.
1990 Peugeot 205 GTi 1.9 // 1991 Peugeot 205 GTi 1.9 16v // 1992 Peugeot 205 GTi 1.9 // 1999 Peugeot 306 HDi Estate