? Thermostat ?, do you have good heat, may make the computer ( ecm ) assume your on cold start up.
The oxygen sensor on the 1999 Oldsmobile Cutlass Sierra is located on the lower exhaust. If you need to replace it, they are available for about $20 online.
DEX-COOL
None
The 1999 Oldsmobile Cutlass OBD 2 port is under driver side dash left of steering column
dextron / mercon type 2
Begin by loosening the tensioner pulley on your 1999 Oldsmobile Cutlass. Put your serpentine belt around the pulleys. Tighten the serpentine belt with the tensioner pulley.
take the complete headlight assembly loose or out to get to the bulb.
You fill the radiator through the overflow tank.
Follow the top radiator hose down to the water outlet on the engine; the stat is in there.
Just like the radiator on the 1966 VW Beetle.... because neither exits. The last American carbureted auto engine was a 1990 Oldsmobile.
Replacing a thermostat on a 1999 Oldsmobile Cutlass is very easy to do. First you will find the thermostat by following the upper radiator hose. It is under the exhaust crossover. The thermostat has two 13 mm bolts holding it in place. Take the bolts off to remove the thermostat and replace with a new one.
Between the engine and firewall labeled TRANS. Under the Air Filter/ Intake box there is a red cap on the transmission for putting in fluid. There is no dipstick that I know of on a 1999 Cutlass w/ 3100 "J" motor.