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Q: Trouble Starting, and sometimes doesn't start at all - Dies at idle from time to time.

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To start off, I just cleaned out the idle air control valve today and it seems to have made my car be able to easily start and run fine. There was only one time after doing that where it couldn't start right away, which may be due to getting throttle body cleaner in the system. I've had problems before this where it would crank but wouldn't start, and then at times it would start but have very low idle that I had to give gas to in order to keep it going. Before cleaning the IAC valve, it had codes P0171, P0335, P0340, and P0446. I am curious if any of these codes would be linked with my cars symptoms. Again, it seems to be running fine now, but there have been plenty of times where it seems to be fine, and then it will randomly not start after being left for a while. Before cleaning the IAC valve, it would idle around 500, and now it's between 650 and 750 after it's been running for a while. Mainly curious if those codes when stringed together can pinpoint a problem area.

My car has 110000 miles.
My car has an automatic transmission.

A: Hello. Cleaning the throttle body and idle ...

Hello. Cleaning the throttle body and idle valve may have been needed, but the intermittent starting and dying symptom can be the camshaft and crankshaft sensors. These are the codes P0335 and P0340. The code P0446 can be from the purge control solenoid malfunction but would recommend the other sensors repaired first. The code P0171 is the system running lean and can be from a vacuum leak or from the dirty throttle body and idle valve sticking (you may have fixed this code). If you want to have this problem scoped out more thoroughly, a certified technician from YourMechanic can come to your home or office to diagnose the starting issue and pinpoint what needs repair.

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