Help Vec 1 low reading

[ViperDave]

Ok so anybody got any ideas on this.

Normally the VEC 1 meter does the usual dance of the lights but on a couple of occasions now after a bit of hard driving and a fairly warm engine I have had the vec 1 read really low, ie when you would expect the red light to be on I have no lights and when you would expect a blue it only gets up to orange. (even if I zero out the vec 1). I also sometimes get a carbon/sulphur smell when ******* the gas. Does this indicate that my O2’s are reading low and therefore the vec being below scale and the engine throwing more gas in to compensate hence the smell.

Do you all think I should replace the O2’s or could it be something else?

Ps it’s a 97 GTS stock except vec 1 K&N’s and Corsa cat back

 

[PRVT JET]

what do you have the "high" set on? If your at -20, trying going to -16 and see if it will richen a little more. Better yet, go back to zero on both dials and drive around for a few miles. Than you can set the vec1 again, make sure you follow the direction that came with it.

 

[ViperDave]

The high was still set at zero and the low was only a few notches positive as I haven’t really got it tuned correctly yet. When it started playing up I set it back to zero but it didn’t change much. It still seems to go up and down just shifted down the scale so when its lean there are no lights.

I am just a bit worried with all the lights going out that it may be the O2’s or something especially with the carbon smell under acceleration

 

[newredrt10]

Are you talking about the air fuel indicator. You should have lights all the time. If you are off the scale the light at the end of the indicator should which direction the mixture has gone.

 

[Sean Roe]

Hi ViperDave,
That's the good thing about having an air / fuel meter in the car. It helps show you when something is wrong, even before the PCM picks up on it and sets a check engine light.
Most likely, your upstream oxygen sensors need to be replaced. The normal wiring installation has the meter reading from the right upstream, but I'd replace both as normal maintenance.
I've had some people call us with questions like this only to find out their fuel filters were clogged also.
Regards,
Sean

 

[ViperDave]

Thanks Sean. Part of the reason for getting the VEC was I was suspicious of the mixture setting due to the smell when ******* the gas.

Today after the battery disconnect the car seemed to be running great but then when it started to get heat soaked and after it re learnt the engine it seemed more sluggish. It started to loose lights when I started it up after sitting for a bit so it seems to be worse when it is hot.

Now do I look at this as an excuse to put some RT cats on as well while I’m at it