Lambda, MCSF problems... help please!!!
Okay, so the history... my car is a 2.0 JTS and I recently had the number 2 coil pack replaced, then realised the issue was caused (I think) from the thermostat failing, hence overfueling... replaced that, not before it took out the numer 1 coil pack as well, so that has also been replaced. Cleared the errors on multiecuscan, and thought I had fixed the issue... However...
MCSF fault came back again, and reading the codes, I now have the following:
P0481 Fan Relay 2
P0156 Lambda 2 signal below catal.
P0150 Lambda 2 signal above catal.
P1161 Preheating resistance 2 below catal.
P2254 Lambda 2 sensor upstream (ground)
P0300 Misfires detected (generic)
P0301 Cylinder 1 ignition failures
So my questions is what to do or try first... I am surprised by the final one, as I have just replaced the coil pack on cylinder 1, and I havent got a noticeable misfire or lack of power as I did before, so what could that be? Also the Lambda sensor issue(s)... what do I do about them and how easy are they to replace - is there a 'how to' guide somewhere?
Any help, greatly appreciated!!!