I knew needed to replace a pre cat O2 sensorfor a little while now as the engine management light has been on and off. I have just gone to double check the error code and have noticed that there are 2 errors for the Lambda sensor (no signal & voltage lift) and a 3rd saying "Burning fail cyclinder 6".
Could this all be down to the sensor or have I other issues need to get my mechanic to look at?
(I wish I was as clued up on engines as I am computers!)
You haven't by any chance got the codes written down?
The descriptions you have sound like a translation that has gone wrong slightly.
The last code will be misfire, cyl 6, and the resultant unburnt fuel and air will be picked up by the Lambda sensor, and result in a fault code being stored.
The good news is that you lambdas are probably OK still, and all you need to do is sort the misfire.
First port of call is to take a look at the sparkplug.
Check there is no water or oil in the spark plug hole first, as this can be the cause.
Water is from washing engines down, and oil is usually from a leaking rocker cover gasket. A common problem.
If you see oil or water, clean it out, do not remove the plug as you'll want to keep the cylinder clear.
Refit the coil and you are good to go.
If you don't see anything, take the plug out and check the condition of this. It may be blacker than the rest from carbon build up, but a light wire brush will clean it up.
Replace the plug, and now swap the coil pack with cylinder 1. This is the furthest away from cyl6, and see if the problem / code returns but moves to cyl 1.
If so, you'll need a new coil pack.
Depending on how bad the missfire was, you should feel a nice gain in performance after.
Now the light has been on and off on the dash and a month or so ago a local garage hooked up their laptop and said the sensor needs replacing and showed me the graph with the 1 sensor voltage varying wildly.
I was going to pick one up on the cheap and get a friend of mine to fit it.
I have cleared the codes to check again in a day or so.
Would you still say the Lambdas are still OK?
(I have just used INPA to diagnose and will be installing DIS which may offer more clues?)
By the looks of those codes, it might be a lambda sensor either dead or disconnected.
If anyone has been working of the exhaust or under the car recently, that may be the cause.
I would have expected to maybe see a lambda sensor heater fault too.
They don't immediately fit in with a misfire causing it, but they can be vaguely linked, especially as they are both on bank 2. (cyls 4-6)
Pre cat, Bank 2 is the further back of these 2 sensors.
Both are the same, in the front and rear banks.
They can be awkward to access though
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