18 months later I'm still unable to turn off the EML and an auto electrician has checked all wiring, sensors etc and says the cat is the problem. OE parts are a must ! Luckily my MOT garage ignore the light ! Now she's either got to drive it into the ground or buy an OE cat from Honda, beware non OE cats, cheap for a reason.
An new OEM cat for a mk1 car would probably cost more than the car is worth, even secondhand ones can cost £300+. Jocko's right - there's nothing wrong with aftermarket cats, they should do exactly the same job as the original.
To be honest, I doubt that your cat has failed if you are passing MOTs - if it gives good results for the CO emissions tests, the cat is doing all it's supposed to do. Your garage may overlook the EML, but they surely cannot pass the car with a failed emissions test.
I suspect you need further investigation with more advanced diagnostic equipment. It is important that the O₂ sensors are functioning correctly, as they dictate the engine's fuel mix - and an incorrect fuel mix can eventually damage the replacement cat, and then you will fail the MOT on emissions. However, with the EML on, the engine
should run intentionally lean so as to protect the cat - but that may have other consequences, such as reduced power and/or mpg, as well as poor emissions results.
The fitment detail on euro car parts says Euro 4 - check OE ? What that means is a mystery to me & the guy on the end of the phone ?
I presume that means the part is type approved for Euro 4 emissions vehicles.
A general tip: One of the less obvious problems encountered with a new front pipe is the manifold joint - they can take a bit of fiddling to get the fire ring air tight, and a leak here may throw up a sensor fault, poor emissions, and may even damage a new sensor. No sealant or exhaust paste should be used on the joint either, as that can also kill sensors. A tiny leak will soot up, but then the EML will still need resetting - and you need the correct diagnostic tool to do that.
