Hi guys

I have a 55 plate fiesta 1.4 petrol. 15 year old car I know however it’s been a day or two that when I turn the engine on there’s a loud rattling coming from the exhaust pipe I’m guessing. It also sounds like a modified car, you can hear the pops and bangs like it’s an Rs3. It’s only a fiesta though sadly. My guess is the exhaust pipe has Dixon extend from the exhaust box???Any idea of what that could be and how much to fix? 
 

thanks in advance 

There are a few exhaust centres that will take a look at it for free and give you a quote if they diagnose it as an exhaust system fault (Kwikfit, National etc).  When they get old, they rot and rattle and if it rattles it could easily have a hole in which would give you the light aircraft engine sound.  Pops and bags?  Could the lack of back pressure make things erratic and cause this?  Eliminate a shot zorst first.  Otherwise, I’ll definitely stand corrected : - )

Update. The car is fixed.

I took it to a local garage and he said the exhaust box had a hole in it so well done to marineboy for guessing. He put an aftermarket exhaust box and I paid £130 for labour and part. The car sounds a bit different because the box is new and he said it will take a while to sound like before. 
 

£130 sounds good or nah?