Got the car a few months ago, here’s some info which I’m hoping will be sufficient for someone to at least point me in the right direction.
The car was MOT’d the same day I got it which put my mind more at ease about making the assumption that the P420 fault which was showing would most likely be a sensor issue. It never occurred to me that a car could pass an MOT with a hole in the CAT. I now know it can. The post CAT sensor behaves exactly as would be expected ie pretty much identical to the pre CAT sensor. Borescope inspection confirmed the damaged CAT.
What, if any affect should I expect that to have on the car’s performance?
I’d read enough before test-driving the car not to expect miracles, but I wasn’t near any roads where it would be possible to check the top speed so the opinion I formed was simply that it wasn’t particularly inspiring to drive but as a first car for my girlfriend, that wasn’t necessarily a bad thing.
However… The reality is, on a flat stretch of motorway it’ll get to 70 ok and all that’s left beyond that is a painfully slow acceleration to 80 (providing it’s not against the wind) and that’s it. The other issue is that at 70 which should be a targeted sweet-spot speed, free of gears changing, is constantly changing between 5th and 6th. Is there a chance that this symptom is simply a bi-product of the lack in power? Ie What I’m having to do with the accelerator to achieve 70mph puts the pedal in a position which is being interpreted by the ECU as “kick-down” behaviour because it shouldn’t have to be as far down as it does.
Obviously “fix the cat and see” might be the simple answer, I’m simply being cautious before I start to throw money at it.
Hoping someone can shed some light.
Thanks for listening
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