Which O2sensor? You have more than one.
December, 8, 2012 AT 12:38 AM
What is the trouble code you pulled from the ECM. If that's what made you think you have an O2 problem.
December, 9, 2012 AT 2:00 PM
Hi my engine is sr 1600cc 8v rpm is up and doun in cold start
December, 9, 2012 AT 6:19 PM
Have someone check the basics: - stored trouble codes (warning light does not need to be on for a code to be stored)
- vacuum leaks
- throttle body (check for dirt build-up, clean and adapt (if applicable)
- temperature sensor (correct resistance when cold)
- fuel pressure
- fuel flow (demand from the engine) is different when the engine is warm. Maybe not enough when cold.
Too many things that could be at fault that I / we can not check over the internet.