Emissions light - intermittent

[MattS]

For a while now the emissions warning light comes on a and stays on after a cold start up. If I let the car warm up for a few minutes and then re-start the engine the warning light stays off. I.E There is only a problem if the car is very cold...

Does this sound like a dodgy sensor?

Thanks,

Matt - 1998 3.2 manual

[NickB]

Hi,

I assume by 'emissions light' you mean the yellow malfunction lamp indicator (next to the low oil pressure indicator on the left hand side of the instrument panel).

The same thing happened to my car (3.2 manual), it would come on when cold and then if you left it running for a few minutes and restarted it would go off.

Turned out to be a faulty o2 sensor. Honda (Gloucester) were able to diagnose the fault immediately (sorry, can't remember the fault code!), although the part took quite a while to arrive.

Not sure on the exact cost to fix (mine was covered by warranty) but when speaking to the the nsx mechanic that worked on it a few months later he said that it was probably in the region of £200 - £300 if this helps.

Out of interest do you find that the engine is holding onto its revs more than usual? - this happened to my car whilst it had the fault.

[MattS]

Hi Nick,

Thanks for that. Sounds like an identical fault. Haven't noticed the revs lingering any longer though..

Interestingly, I filled up with BP Ultraexpensive today (usually use Optimax or Esso Ultra) and the light stayed on instead of going out when I restarted the engine while warm...

I've got to have a 90k service done soon, so I'll have it sorted out then.

Thanks again,

Matt