Exhaust Resonated or Non-Resonated - MOT rules

Ed Hall

Paid Member
Good Evening,

I've ran my 197 with non-resonated and resonated Miltek sections. Before my last MOT I was a bit worried about the current MOT legislation. So I switched it to my resonated section, so it wasn't too loud and had a resonator as per the rules.

But with it being remapped it was always better with the non resonated section, if anything it seemed quicker.

So my question is would an MOT inspector know if the resonator was missing? At the end of the day its £100 for non resonated section and an hours labour at the tyre place to switch it over, but it is a bit of a faff.
 
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Good question mate am not too sure either probably depends on your mot tester on the day, But hopefully some one with better knowledge will know the proper answer
 
Good Evening,

I've ran my 197 with non-resonated and resonated Miltek sections. Before my last MOT I was a bit worried about the current MOT legislation. So I switched it to my resonated section, so it wasn't too loud and had a resonator as per the rules.

But with it being remapped it was always better with the non resonated section, if anything it seemed quicker.

So my question is would an MOT inspector know if the resonator was missing? At the end of the day its £100 for non resonated section and an hours labour at the tyre place to switch it over, but it is a bit of a faff.
What I’ve did last year before my mot. Was to get the garage to check the emissions so I knew if it failed with what I had I’d need to changed... removes any guess work
 
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im sure they can't possibly know what these system are meant to look like..as long as you have you cats in place you should be fine..just my opinion though..never had any issues with my MOT place
just had my done this week..
 
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I don't think resonated or otherwise will be an issue for MOT. Surely that's more about emissions? I'm running a resonated system with a sports cat. My MOT is in June & I'm waiting to see the implications of the new rules when the car is tested. Fingers crossed!
 
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I don't think resonated or otherwise will be an issue for MOT. Surely that's more about emissions? I'm running a resonated system with a sports cat. My MOT is in June & I'm waiting to see the implications of the new rules when the car is tested. Fingers crossed!
You’ll be fine John, mine got tested with a decat with no problems and that was on new mot system
 
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You’ll be fine John, mine got tested with a decat with no problems and that was on new mot system

Glad to hear that. Still running standard manifold which passes the emissions test so will keep it as is until my MOT (whenever that is???). Then it could be Ktec manifold time...will need to invest in a high flow sports cat to get it through MOT then...
 
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missing silencers are not really an mot issue only leaking ones

new test is more around "missing" cats/dpf so be careful car can meet the regs but if something as obvious as a missing cat then can still fail
 
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missing silencers are not really an mot issue only leaking ones

new test is more around "missing" cats/dpf so be careful car can meet the regs but if something as obvious as a missing cat then can still fail

what is a cat?:tearsofjoy::tearsofjoy:
 
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Ultimately it depends on how fussy the MOT tester is. They can fail it if they wish because the exhaust is louder than reasonably expected for the type of car it is on. Plus one look at it from under the ramp will show that it's aftermarket. Will it fail however? I'd say it's unlikely to but i'd recommend you ask them in advance if it will pass with the non-res section on.
 
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