Missfire after driving through floods

[98elise]

My wife drove her MX5 (slowly) through a flood, probably about 4 to 6 inches deep. Afterwards it started misfiring between 2-3000 revs.

I took it on a reasonable drive to get a bit of heat in the engine and its now seems fine. My question is whats that low down on the car that would be affected by floodwater that deep?

[Oldandslow]

Nothing I can think of on the Mk 1 and 2 but it could have splashed up around the coil pack or into the plug wells.

Is the under tray still fitted?

[98elise]

Yes the under tray is there. I didn't know they had one until I was looking for damp on the engine. Everything looked dry, and a coating of WD40 didn't improve things. All seems fine now though.

[Rickyy]

Lambda sensor is pretty low down on my MK1. No idea if that could cause a misfire though.