(T) Another newb with 2 questions!

Hi everyone. My first forum post so please let me off if I do something stupid!Also I don't know what to do with these smilie things yet.
I am a world weary middle aged geezer who feels like an oap (tired and skint).I have bought an X Reg Punto light blue, 1.2 8v with 60k - ish on the clock. The car is in good nick bodily (unlike me) and runs well (even more unlike me). She does around 42mpg even at 70 plus a bit on the mway.We managed over 370miles + on a run to Scotland on a single tank.Handling is a bit woolly,but no bad thing when you have a young lad (son) driving it I reckon as it doesn't encourage fast cornering. I have had the sump replaced (it was weeping oil) and the clutch 'cos it was juddering like hell. Now I have noticed that the back box is blowing a bit. Some people seem to be saying it is a one-piece from the cat back, but others say you can get just the back box. Anybody know for sure which it is, and any idea of cost? Also the exhaust manifold heat shield is held on by 2 nuts on the top that need tightening up and I think only 1 at the bottom.The reason being the others have sheared.I am wary of tightening up the remaining bolts in case they sheer off as well. If they do, does anyone have any advice on drilling the remains out? Some chap I spoke to suggested replacing the bolts with self-tappers.Any views on this?
I am enjoying reading the forum very much.It is good to hear that so many of us share the same creaks and squeaks (on the car that is). But what a fun car ! Thanks folks.

I can't help you there myself sorry, but only 42mpg from an 8v?!?!??! something wrong there! I have the more thirsty 1.2 16v and the lowest i've ever seen it recently is 43!

oh, and welcome to the forums!

the exhaust is one piece

check: onlineautomotive.co.uk or shop4parts

they have pics on there for the required exhaust. the ones i have replaced have alwasy been 1 piece form the cat back.

drill out where they have sheared and re-tap with the next bolt size up - should do the job.

please excuse this total rubish

the exhaust is one piece or can be bought in two pieces with a joining sleeve so you can cut pipe to fit depending on witch bit has gone front pipe or back box

dealers like to sell you the single piece from cat back as it makes them more money i'm sure

but fiat definitely have
1 hole exhausts
2 back box and sleeve
3 centre pipe and sleeve

not only this a dozen other motor factors will sell you all the different bits of exhausts for any car after market of course

if you get a flat punch andgive the bolts ontop a good few sharp hits on top with heavy hammer

that will sometimes shock them enough for you to undo them and replace with another bolt and big washer or whatever you feel would secure the heat sheald a bit better you will probably find that the heads dont resemble any sort of bolt sise so use an 8mm socket and hammer it on that way you wil be making it into an 8mm head at the same time as loosening it

Thanks for your replies guys. I appreciate it. I will shop around for the exhaust back box, and try to persuade the remaining heat shield bolts to accept a bit of tightening up using your suggested technique.
O'h, and the 42mpg was with a fair bit of weight on board and perhaps we were going a bit quicker than we thought! The exhaust still looks a bit sooty around the tail pipe. My old Dad used to tell me that after a good run a well set up car's exhaust should be very clean inside.Don't know if that's still true or not.
Anyway, great advice. Cheers!

Update on the loose heatshield. Some WD40 on the bolts, some sharp taps with a hammer and chisel, and some careful socket work, and hey, they came out! So I put the bolts back with a couple of thicker washers, and tightened 'em up again. Rattling cured, for now at least!
Thanks guys once again.