QuestionI have a 97 cirrus with engine code 21(o2 sensor). My problem is when I start the car it stalls you have to use both feet to keep it running if you stop, one on the brake and one on the gas. After a few minutes it is fine but if you turn the car off and try to start it right back it will do the same thing. It doesn't matter if the car is hot or cold. But sometimes it will start better if it is warmer outside. would the O2 sensor be causing this or could it be something else.
AnswerHi Travis,
In general the O2 sensors will not be brought into play until the engine has warmed up enough to operate in the "closed loop" mode. Before that it won't affect the engine's performance.
I would wonder if the egr valve might be sticking open until it warms up, or a vacuum leak is present that seals itself.
I had a similar question from a Cirrus owner who couldn't get his car to start, and here is what I suggested:
"The first thing I would do is check the mechanical function of the egr valve which is located along a pipe that runs from the left exhaust manifold (on the side of the engine facing the front of the car) to the intake manifold area (where the incoming air in the large rubber tube enters the throttle). That valve is metal and has a round fitting with a vacuum hose attached, mounted on the top of the valve, and the round part is attached to the main body of the valve by a sort of saddle. Inside the open saddle you will see a metal rod (with a slot) that connects the round top fitting to to the valve body. That rod is a stem on the valve and it is supposed to go in and out in response to the engine vacuum which varies with RPM and throttle opening (gas pedal position). Take a spray can of WD-40 or other penetrating lubricant and spray the stem where it enters the valve body and then use a regular screwdriver blade tip inserted in the slot to lever the valve in and out to try and free up its motion. Also check all the rubber vacuum hoses associated with the valve and a nearby vacuum solenoid valve. If the valve seems to open (against the action of a spring) and close firmly by the spring action when using the screwdriver blade to facilitate the motion, then you should be able to now start the engine. You can, once it is idling, check that the valve stem moves when you rev the engine from idle to 2500 rpm and back to idle. If it still won't start, then removing and cleaning the interior of the valve, or buying a new one if it seems too crudy and corroded inside, is the next step to getting the engine to start."
So see if that might be what is going on. If not, then I would look over all the hoses that are attached to the intake manifold for leaks or loose fittings. Another possibility is the idle air passageway in the throat of the throttle body is partially clogged, so remove the air intake hose and try cleaning that small opening and also clean the throttle plate (both sides) with solvent.
These are the usual cause of poor idle. One last possibility is the idle air control that regulates the idle air passageway is cruddy, so that should be removed and cleaned up to make sure that it is free to regulate the air passing thru the idle air passageway (clean the tip and the hole that it operates thru in the body).
Please let me know which, if any, of these suggestions seem to fix the idle problem.
The 21 code should be addressed by checking the sensors' wires and if none are found to be broken then you would probably want to have a code readout done with a plug-in unit because those have the potential of telling whether the problem is with the upstream or downstream sensor. You might be able to get a free readout at a parts store (e.g. Autozone).
Roland
