Induction note change/ pops and bangs on downshits

[NWDSdaz]

My cars induction note seems to have changed this evening! Also feels a little sluggish and pops and bangs on downshifts driving normally when it previously only didn’t it occasionally when pushing on. It does almost sound like it blows a little under load when passing stationary objects with the windows down.In the last month it’s had a full service with genuine parts, and had the belts and dephaser done last week and was running the best it had in my ownership until this evening. The cars also had a gravity manifold and relevant power flex bushes about 8 months ago so that should hopefully rule that out. There’s no lights on the dash and no codes showing on my basic OBD reader. Anyone had anything similar?

thanks in advance

 

[NWDSdaz]

After someone suggesting it sounds like the manifold, I’ve been under the car this morning! Manifold seems good, and the flexi is in good condition. No blows from the exhaust it there was a pretty rusty clamp just after the car so I replaced this with a mikalor clamp. Seemed a little sluggish when cold but once up to temperature power seemed ok. Just seems to pop and backfire a lot more than previously on down changes and over run! I’d really like to get to the bottom of it before mapping next month.

 

[NWDSdaz]

After a little googling came across these

No Power

today i went to work and she drove like she normally does, not missing a beat. when i started it up to go home it seemed fine, reversed out and turned around at a end the road, thats when the engine jumped about on idle and conked out. this happened about 3 times when i tried to restart it. the...

clio197.net

Thinking it could be a good place to start…..

 

[RSRowe]

I don’t think aimlessly buying parts based of google searches is the best way to spend money tbh.

You state you’ve had a decatted manifold fitted, and that you now have more pops and bangs. I would say that what you’re hearing is completely normal.

As for sluggishness. The Clio’s are notoriously bad for flat spots when you mess with the exhaust

 

[NWDSdaz]

@RSRowe The manifold and decat have been fitted around 8 months and this has only started to happen over the last few days.

I know messing with the exhaust causes flat spot issues, and the car is booked in next month at EFIfpr mapping.

 

[RSRowe]

I’d not spend anything until you have your dyno session then tbh

 

[turkie172]

The connection from the middle silencer to the manifold is not straight if you check I had what I thought was blowing from the manifold but what it turned out I loosened off the manifold clamp then the joint from the middle box to the back box. By rotating the silencer so the middle box was more up into the middle heat shield tunnel I tightened both clamps again and the problem fixed. I have a Akra Evo so the pipes don't have multiple joints so it was easy but the 197/200 and the 172 Clio the exhaust has a constant twist force due to very few mounting points so if a clamp is not tight enough the weight of the exhaust can allow it to sag and the alignment change on the 197 manifold joint and cause leaks.