My car currently has multiple fault codes:
P0031 - Heater control unit (HO2s)
P0037 - Heater control unit
P0403 - Exhaust gas recirculation
P0342 - Camshaft sensor
My mechanic says we will need to replace the O2 sensor and it will fix it, but reading the various articles online tells me that a bad camshaft sensor is more likely to cause engine stalling during idle. Any idea what's the best way to go about it?
Car: Chevrolet Spark 2010 Petrol
From your codes the only major one is the Camshaft Sensor, replace that and give it a try. Other than that nothing else from the above codes can stall your engine.
The EGR would throw a check engine light but the engine itself would not stop cause of this. The heater control units are for the comfort of the passenger but not for the engine.
The cam position sensor is not that expensive from what I remember I think it was around 20 USD.
P0031 & P0037 are both heater circuit low voltage codes. While the heating elements may be bad, I'd check wiring first. Both sensors should be getting power from a fuse and a control signal from the PCM.
As to the P0342 this is another circuit low voltage code. You should be checking for 5V reference from the PCM, low reference/ground from the PCM and signal to the PCM.
Note that the camshaft sensors are used to correlate the camshaft and crankshaft and don't directly affect the ignition system.
If the EGR valve were stuck open it could cause the car to stall at idle. Though I'm not sure if the car actually has one or not you'd have to visually confirm. I think your car has 2 camshaft sensors and uses valve timing to perform EGR functions.
