Hi. So I have a decat bit not yet had the car mapped as barley use it but will be getting it done in January. So I've had the check emissions come one a few times and just rest it with my scan gauge. But last week enter for a short drive and knock sensor came up alongside the emissions. Car runs fines but was dead with no power when the fault came up. So could they be related or is the knock sensor gone and need replacing. It's the one above oil filter to the right slightly? Anything I need to be aware of so I don't kill my car. Thanks Thanks
Bit of a tough one, as the decat isn't mapped in it could be that the knock sensor detected knock and put you on a safe conservative map to save the engine. Or your knock sensor could be giving duff readings. I'm not 100% sure on the megane as haven't looked into it completely. But on my old Clio you could disconnect the knock sensor and it didn't seem down on power etc. I'd be leaning towards the knock sensor saved your engine personally and I'd go get it mapped ASAP. As I have read that decats can cause your car to run slightly lean etc when not mapped in. When you say you don't use it often, how often? Has it been filled with normal petrol and left to stand for a couple of months prior to using it? As if so the RON rating of petrol deteriorates over time so could be that too.
Just seen that you use premium fuel, so ignore the petrol bit unless it's been sat for ages. Has it been mapped at all I.e. generic stage 1? If so by who etc etc
Hi bud. Maybe use it once a week for 5miles. Not usually a full tank. It was mapped when I got it stage 1 flash map. It had been fine for ages but changed to shell from tesco and them it started. It's been ok for ages. I've bought a new knock sensor. Would I be able to hear any noises related to the knock sensor
Nah the knock sensor is basically just a microphone tuned to listen to specific frequencies so you can't really tell from looking at it if it's gone or anything. How long Has the petrol been sat in your car for? As like I said the ROn value degrades over time so if it's been there for a while it may no longer be 99/98 Ron. It degrades quicker the more air in your fuel tank too. Who flashed the map? Reputable tuner? I remember seeing that premium fuel can degrade down to 95 Ron in 7-14 days depending on conditions.
Ah I see. Was sat for 2 weeks just before reserve light came on. Could it be fuel related. Tunnel is a friend does mobile tunning. But it's going to SMT in Jan so want it spot on for then.
