Vectra - CAT and Petrol smell connected?

Hi I have a couple of problems with my vectra. I recently bought an R
reg 1.8 Vectra, Whilst driving on the motorway I the car would jerk
and not pick any speed up, i pulled it into the garage and they said
the coil pack had gone (whatever that is), anyway I paid £100 for a
new coil pack to be put in. A couple of days later, the exact same
problem only this the car wouldn't go past 20mph. i pulled it into the
garage again and now they said the catalytic convertor has gone and
extra £200. As you can imagine I wasn't very happy as i described the
same problem twice and was quoted for two different parts. They say
that problems with the coil pack is what caused the CAT to go. Does
anyone know if this could be true? Anyway after having a new CAT put
in, Every time I would put my foot down on the gas, it would make a
noise, a sort of hissing noise, and now I can smell a lot of petrol
from the car but there doesn;t appear to be a leak,Does anyone know if
this smell problem could be linked to the CAT being put in ??? Any
help much appreciated Thanks.

 

If excessive fuel hits a hot catalyser, it will produce an awful smell. What
you have described sounds like high back pressure, which is probably cause
by a blockage in the exhaust system. Even a new cat would be suspect. I
cannot qualify saying it didn't need a coil pack, but at the moment I have
my tongue firmly inbedded in my cheek. Find a decent exhaust company, and
ask them to confirm if there is a blockage. The next step would be to have
the codes pulled, as a bad camshaft sensor will cause the engine speed to
drop, because the management will default to mpi from sfi, usually limiting
the revs to approx. 3500, however the mil will come on in this circumstance.

 

Faulty coil would cause a misfire and the unburnt fuel would ignite in the
Cat thereby overheating the Cat. I am not saying that this is what
happened, but it is quite plausable.

 

, as a bad camshaft sensor will cause the engine speed to

funnily enough
I had a citreon xantia once upon a time
(don't all flame me please)
and the coil went on that causing very similar problems to those described
regarding temperamental performance
a new coil fixed the problem
but at the next mot it failed on emissions
and did require a new cat thought there was no other symptoms than the
emissions fail for the cat fail