This is doing my head in now, not sure what's wrong. Had my car on diagnostic and these codes came up saying lambda sensor bank 1 and 2, had them replaced twice and still the EML is still on? I've had to change my alternator because the battery wasn't charging and my car died and had it recovered. So I'm stumped? I've taken it to an auto electrician and they can't find any obvious faults? If anyone can help id be over the moon!!
Also noticed that the AC pump comes on after start up but no light on the switch in the car? And the fans come on when the car is started up? Is it all related? I need some help!!!

 

When the air con comes on. Are the heater switches on the front windscreen??

I got the p0420 code for the front lambda. I made a bracket for it cause my lambda sensor connecter is just lying on the bell housing.

Also I know my st has had 2 rear lambdas. The ones that have been fitted are a bit too long and the driveshaft catches them and damages them.

 

You shouldn't have bank 1 and bank 2 codes as your car only has bank 1, pre and post cat sensors. As glenny says, check the vents aren't set to windscreen as this will automagically bring the ac on.

 

Yes the turn switch in the car is set to windscreen, I didn't realise the ac would be used for that? My car takes ages before it has heat coming through the vents aswell.

 

Well both p0135 and p0141 comes up on 3 different diagnostic tools used, and when we have looked those up it says bank1 sensor and bank 2. It's causing a problem every now and then in 1st 2nd and 3rd gears where the car judders and doesn't accelerate? As far as I'm aware everything has been checked and nothing can be found except the EML on the dash and the codes found?

 

If you look up these codes they relate to bank 1 sensor 1 and bank 1 sensor 2, which is what your car has, no mention of bank 2 which is for cars with 2 manifolds and cats. Lambda sensors are a common failure on the st170 so I'd be looking at both of them.

 

No reply whatsoever.

So, your "electrician" isn't quit as good as you think.

Changing the oxygen sensors (especially the 2nd time) was very ill advised and a waste of money.
Who gave you that advise? The first time? And the 2nd time?

 

Do you not have a hand book for your car?

Both our focuses warm up quick i think.

 

I don't think he is either, had the car for 3 days and couldn't find any "obvious" faults so he's said. I was wrong when I said bank 1 and bank 2 it's bank1 sensor 1 and bank1 sensor 2 o2 heater malfunction. Codes p0135 and p0141, 3 different mechanics advised I should change the lambda sensors. I'm stumped, my car seems to have a major electrical fault that's all related to the codes?? Possibly?? I'm not a mechanic myself I'm a welder haha