Hi Guys
I am having problems with my sc4. I am getting terible gas mileage and my exhaust smells a little smoogy. In addition my check engine light intermittenly comes on and goes off. I am not sure how acurate this is but I remember filling up with gas and then the light went off but it came back on when it went to half a tank left. This only happened twice though. Please help.

thanks

 

Bump! What's the mileage? O2 sensors?

 

This can sometimes happen if your gas cap isn't sealing properly. Do you have traction control and, if so, does the "Trac off" light come on at the same time?
It's most probably your upstream O2 sensors, which should be replaced in pairs. There are lots of threads relating to this.
Good luck

 

Thanks for responding my mileage is 296k and I think the O2 sensors are original.

 

I don't have traction control. Ok I will check it out..

thanks

 

Update and a little more inoformation. I put about 22$ of middle grade gas in my 400 today. I left the car running while I went in to pay for the gas. I then filled and when I got back in car the check engine light went out. What does this mean?

 

No idea, but my 1992 SC requires premium fuel only. Try using the highest grade fuel available in your area and see if that helps.

 

I have a similar problem but my CEL stays on. I believe my prob is the O2 sensors.

 

I always use premium fuel. Maybe I will try some 110 one day..


I think that is my issue as well but that is an expensive guess you know..

 

^93 octane is enough for me. but when I first bought my car i put in reg and it backfired a couple times when i slowed down but never showed a CEL.....

have you got a diagnostic? it should show up even if the lights not on.