Lambda Sensors - Does it matter which goes where?

I am just finishing off the fitting of my new Stainless Exhaust system and need to put the Lamda sensors in place. During the proceeding I managed to get muddled which came from which pair of pipes.

On close inspection the Sensors do appear to be different.

One is marked - OHA-333-H16 and the other is OHA-333-H29. They are also marked OM7 and OM15 if that helps anyone. Google is coming up blank for each of these numbers!

How do I tell which goes where?

 

I just spoke to the local Honda Centre but he was unable to help me.

Please can someone take a quick look. All I need to know is which sensor (H16 or H29) takes readings from which pair of pipes.

PLEASE!!

 

Often times if the sensors are not meant to be interchanged (at least on cars) the connectors will not be exactly the same. They may look similar but you can't plug them in wrong. Have you tried to see if the connectors will reverse? If they will plug in reversed they are probably the same sensor regardless of markings. Lambda sensors are internally "tuned" so that every sensor has the exact same response to a control exhaust mixture. The marking may indicate nothing more that the resistor tune value or a manufacturing time/date.