200 10V stumbles, poor mileage

[Konstantine Bogach]

I am asking for a timeout until next weekend.  I don't have a garage 
:(   I will check grounds and oxygen sensor.
Thank you all very much for responses.

Konstantine

On 12/19/2009 10:05 PM, Huw Powell wrote:
>
>
> Konstantine Bogach wrote:
>> Hi Huw,
>> forgot to mention O2 sensor:  it is only one year old, maybe two.   
>> But... who knows, you are right, that would be an explanation.  I 
>> checked duty cycle and it sweeps around 50% - same as it was before 
>> the car started to stumble.   Would it be a proof of good oxygen sensor?
>
> I think so, yes.
>
>> Can I disconnect oxygen sensor connector when measuring? 
>
> No, not to test the OXS, anyway.  But disconnecting it might provide 
> an interesting data point.
>
>> Would using a scope give more definite test?
>
> Possibly, but I've never used a scope.
>
> Let's go old school - how good is the ground from the computer to your 
> engine?
>