Vauxhall Astra G Petrol - Help astra cuts out and splutters - mullins24
Hi all in abit stuck ive got a Vauxhall astra g mk4 1.8 16v about 4week ago I stupidly drove through some deep water up to my head lights no water got in the air filter the car drove fine afterwards an hour later I parked it up for the night the next day it all started when I drop my clutch not all the time three times out of ten the revs just drop and it dies starts back up  everytime no problem it also splutters when I accelerate alot more if I set off up hill I don't and haven't had an engine management light on it does work tho it showed no faults on the tech2 Diagnostic I'm fault finding blind the spark plugs were nice and golden brown before this now there all black and sutty (dry) I've had three sets in  the things I have done are as follows 

1) Spark plugs changed
2)EGR valve cleaned out+blanked all ok
3)Coil pack new and taken bk old ok
4)All electric unplugged wd40 over nite
5)diagnostic test no faults known
6) new air fillter
7)mass air flow sensor new
8)striped cleaned throtle body 
9)fuel relay
10)cleaned crankshaft sensor 
11)changed camshaft sensor
12)cleaned lambda sensor 
13)new thermo (stuck open)
Vauxhall Astra G Petrol - Help astra cuts out and splutters - madf

Failed coolant temperature sensor.

Air leaks... (oil filler cap? . all hoses, all EGR pipes clear?)

Vauxhall Astra G Petrol - Help astra cuts out and splutters - doofer

Check the cat, the thermal shock of hitting the cold water may have shattered the internals causing a blockage.

Vauxhall Astra G Petrol - Help astra cuts out and splutters - mullins24
Thanks for the reply how would I check the cat?it does back fire when off the throtle never used to do that and Olso smells rich
Vauxhall Astra G Petrol - Help astra cuts out and splutters - mullins24
Hi thanks for the replys my heater gauge works fine now I've put a working thermoset in can the temp sensor still be faulty if it's showing readings?sorry I didn't mention I've Olso changed the oil and oil fillter,can't seem to feel any leaks on any vac pipes or throtle body gasket or egr gasket the egr is electronic no vac pipe
Vauxhall Astra G Petrol - Help astra cuts out and splutters - mullins24
I Olso seam to have abit of a ticking or could be a rattle but can't seem to pin point it.were I go it moves lol thought it was my crank sensor as it seems to be low down going to rip the exhurst of and shake the cat what happens if I was to be that would that give me the rich smell cutting out and splutter/misfire causeing suttee plug, would it be a scrappy job or unblock it n put it back on
Vauxhall Astra G Petrol - Help astra cuts out and splutters - doofer

No need to take the cat off, just give it a thump with your hand, if it sounds like a baby's rattle then it's broken.

A decent tech or exhaust fitter will be able to tell if the exhaust is choked just by putting a hand over the tailpipe. If the pipe is clear the gas will 'pulse' as some air is drawn back in, if it's choked it's more of a steady blow.

If you want to get more technical you can remove the pre-cat lambda sensor and screw in a pressure gauge, or fit a vacuum gauge to the inlet manifold.

Not sure if a choked pipe would cause all your problems, but it's simple to check, if only for elimination purposes.

Vauxhall Astra G Petrol - Help astra cuts out and splutters - mullins24
Hi again thanks for the reply I've jacked it up and give it a few hits with my hand it's defenatley broken inside looked on the Internet symtoms are engine run alittle hotter mines nealy at 90 most of the time backfire/splutter and stall Olso using slot of fuel can't think of what else it could that water could damage the rattle only started about 3 week ago I'm hopping it is of to a friends garage in an hour to cut the cat off for free to see if it fixes it before I replace with a new cat I've searched high and low for a water related answer that I would of missed garage after garage I've been to joined honest jhon and straight away someone that finely has time and knowledge with a different possibility instead of what I had done already egr throttle body ect,thanks for you time
Vauxhall Astra G Petrol - Help astra cuts out and splutters - mullins24
Car now runs fine thanks alot