Why is my car running rich?

[BlackedOutTib]

I have a '99 Tibby and just replaced my upstream O2 sensor. Awhile back I got a CEL for it and just now got around to replacing it. Anyway, for some reason, now when I start the car I can smell it running rich for about 5-10 minutes. It is cold here now (Ohio), but it never did this in any previous winters. And I've only noticed it since I replaced the O2 sensor.

[Tugger5000]

Have your MAF checked out. Mine killed the cat before it threw the CEL.

[Kemper]

Don't want to hijack the thread, but what does smelling rich smell like? I ask because every once in awhile my car's exhaust smells sickening strong (stronger than usual).

[tibby01]

maybe the TPS:??:

[BlackedOutTib]

Originally posted by Kemper
[body]
Don't want to hijack the thread, but what does smelling rich smell like? I ask because every once in awhile my car's exhaust smells sickening strong (stronger than usual).
[/body]

If you've ever owned or been around a carbuerated engine, you'll know. You just kind of smell fuel. It's definitely distinguishable from exhaust smells. You may possibly be burning coolant off from a bad head gasket or maybe even oil.

[BlackedOutTib]

Originally posted by tibby01
[body]
maybe the TPS:??:
[/body]

How could a TPS cause a car to run rich? I've never had any idling problems or anything like that.

[VALKYRIE YB70]

Reset your ECU......here`s how :-
http://www.ukhcc.co.uk/Knowledge_base/reset_ecu.htm
Cheers,
Nick.