I need to clear a code

[Smithy]

Good evening all. I fitted a new exhaust manifold gasket at the weekend and while I was taking it for a test drive I had an engine code appear. Looking at the engine bay I realised that I hadn't reconnected one O2 censor. What's the best way to clear it without a code reader or is that the only way?
Thanks all

[tomato]

 Can unplug battery, leave for 15 mins or so,check battery drained by pressing horn.

Reconnect ecu will reset I believe

[Topdownman]

As said above, disconnecting the battery will do it, the car will then relearn the settings over the next few miles of driving (10-30 miles?).

Equally, if you have corrected the fault, the car should detect this as you drive and I imagine the code would disappear once the ecu detects the sensor again.

[paulj]

I think the Car Scanner app on android will reset ECU as part of the free of charge offering.  I know you said you haven't got a reader, but a cheapy OBD reader is less than £10 and the app is free.  I keep the reader in the glove box and my phone is with me so always ready for any pesky codes.

[Smithy]

Battery disconnect for 30mins did the job. Thanks everyone.pailj I will definitely look into an obd scanner to work with the phone app.
Thanks again everyone

[Chilli Girl]

Good work James