Q: Car turns over but won't start unless completely cooled down.

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My Nissan 350z is throwing a p0420 code and it starts if I let it sit and cool down then starts right up. But if I shut it off it doesn't start again until cooled down. Mods on the car are cold air intake and exhaust.

My car has 143676 miles.
My car has a manual transmission.

Hi There, Code P0420 relates to the exhaust system, specifically to the catalytic converter, however there are a number of other things that may cause this code to be triggered as well. Other things like a faulty oxygen sensor, a faulty engine temperature sensor, an exhaust leak, a leaking fuel injector or a misfire can also cause this code to come up. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle to further diagnose and repair.

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