what would the cat do to the engine to start random misfires
p0300 code is when the engine is seriously struggling to fire and keep running
mine was intermittent, if he is getting a random misfire at all times then he shouldn't be even driving the car as it could cause serious damage
either the engine is running really lean as a result of air leaks but that should be apparent really with the map sensor unless it is faulty, it could be a blocked or gummed up injector but the ecu would pick up on the specific cylinder rather random, or the engine is overfueling as a result of incorrect engine temperature [cts], faulty fuel pressure, he has already replaced the coil and cts so i would venture further down the fuel injection system in terms of fuel pump , fuel pump relay, fuel rail pressure then injectors and then start on the ignition which could only be the crank sensor, coil and plugs
the lambda's would show up a fault if they were not running at the specified voltages
but i would rule out any mechanical causes as this engine is very sensitive to compression, as stated on the speedster.nl website this engine does not have a cam sensor nor idle control valve, the timing and idle are based on compression and firing
the lambda's would show up a fault if they were not running at the specified voltages
from spending a week speaking to people and reading up on vxhall websites it is definatly a fuel or igntion
he said he replaced the plugs, has he any photos of the plugs so we can see wot they look like