You probably have an oil leak somewhere around the top of the engine. Valve cover gasket, leaking head gasket. When the engine warms up, it cooks it off and you smell it. http://www.autozone.com/servlet/UiBroker?UseCase=S001&UserAction=viewSimpleDiagInfo&Parameters=info
Defective exhaust system.
In a 2004 Pontiac Sunfire, there are two oxygen sensors. One would be located in the exhaust before the catalytic converter. The other is located in the exhaust after the catalytic converter.
The price for a new exhaust system for a 1995 Pontiac Sunfire is between $110 and $253, depending on the brand chosen. The MagnaFlow is one of the more expensive brands.
If your exhaust is getting in your coolant, you have a reeeeeeeeeeeeaaaaaaaaaaaaaaaaallllllllllllllllllyyyyyyyyyyyy major malfunction.
A blown head gasket could allow coolant to enter the combustion chamber from the water jacket. The coolant probably is running out the exhaust on first start-up. More often, you will notice the coolant being pumped out of the overflow as the exhaust gas pressurizes the coolant. You should look for this symptom when the engine warms up. Coolant in the exhaust on start-up and then the coolant overpressure overflow from the expansion tank or radiator happening together is almost sure indication of the head gasket failure.
I'm assuming your asking about the coolant purge valve, there is a pipe that runs right above the exhaust manifold, take a 6mm socket and turn c/clockwise half a turn while you are filling the coolant. Ahen coolant comes out, system is purged. Idle for 20 mins and observe temp and coolant level anyways, cause overheating those engines is not cool at all.
no
An increase in cabin noise caused by the exhaust.
Bad head gasket? Oil mixing with coolant?
Exhaust system. Usually manifold near port(s).
The upstream oxygen sensor is mounted in the exhaust manifold The downstream oxygen sensor is mounted in the exhaust pipe after the catalytic converter
it sounds like your coolant over flow tank is leaking. it is a common problem with these cars. might also check your radiator for leaks or your exhaust for coolant, but if there is coolant in your exhaust that would mean blown heads