running lean

For some reason or another my reader has deleted the thread.

Righto have had a looky in the engine and a fidget with stuff and found one spark plug slightly lose, could this has let air into the engine to cause a fault with the fuel+air mixture and cause lean running ?

I nipped it up and inspected the 3 other and nipped them up. Coil packs were put back on and wiring checked. I have driven 45 miles of 30/40mph and scanned it and no warning has come back weirdly after erasing it.

Not sure if this is just wishful thinking, but perhaps it was the cause.

I'm doing a 80 miles motorway run + 20 town next week so that should be another day to check for faults. As they usually pop up when I'm a long way from help lol.

Just wondering if a lose spark plug could cause this ? also that hesitation slightly misfire feeling is not there, just feels a bit more positive and normal as it was once.

I'm not sure how this spark plug came lose as I serviced it last and torqued it up according to haynes :-/

If it does come back up, and the condition of the spark plugs is still white (although now there white-ish will they go brown if its working ok or do I have to change them now ?) I'll have to investigate further.

The Lambda reading came back withing range of 1v. (cheers harry for the tip)

yes, & yes.

Thanks Dave :)