Audi engine misfire

[maix27]

Hello folks,

Got a bit of an issue with my 97 A3 1.6. First my engine overheated and I found I had a blown (read destroyed)the fuse box (the one on top of the battery) got that sorted but whilst sorting it i noticed an engine misfire and the occasional pop (coming back up the inlet pipe, not through exhaust).

I fitted new HT leads suspecting a poor spark; plugs were cleaned but were nearly new. Air filter is clear.

I plugged a reader in last night and pulled of a few error codes, rubbish ones except one telling me the upper Co2 reader on the Lambda sensor isn't reading (code: 00557)

I'm going to jack it up and clean the Lambda tonight.

I have two questions! One: anyone know the best way to get to the lambda on the A3, I can't see it from the bay.

Two: has anyone had similar problems, lack of power, pop on overrun and misfire on rising revs? Was it a lambda problem or MAF sensor, as I get the impression it's going to be that!

Thanks for any help in advance!

Mike

[Timmolad]

On occasion, a misfire through the inlet could suggest the timing is out but if the car still drives reasonably I doubt that's the problem. The lambda sensor will likely be out of reach, behind the cat, underneath the car. Surely a lambda fault would put the management light on though.

[frank st]

popping back into manifold and misfire most likely to be burnt out inlet valve do compression test to diagnose properly

[maix27]

Cheers for the advice,

Haven't touched the Lambda sensor, to difficult to get to without a lot of effort. Have however taken the MAF out, cleaned it with carb cleaner and the engine's running a lot smoother now, pulls nicely throughout the rev-range. Still has a misfire though. I think i'm going to have a look at the injectors...