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Q: what do codes P1391 and P0340 mean?

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I've been told my car has a misfire before, but that was 2 years ago. So I'm used to a little bit of jerking when driving. The other day I noticed I couldn't drive over 60mph cause the jerk was horrific! Never that bad of a jerk. Felt like my engine was going out. So I tried to drive it under 60 , but it's like it was losing power. The next day it gave out completely, it reminded me of the time I ran out of gas. First time it went out, couldn't get engine to turn over. Had it towed to a mechanic, they said the battery was no good, so I replaced it, then the engine would turn over. So I drove it home, but the same thing happened again the car just stopped moving. It won't accelerate and if u try it just causes the car to stop moving. The radio and light will still work, but the car won't move at all. My friend hooked it up to a scaner. It gave two codes P1391 and P0340. What does this mean? What do I have to buy to fix it? Also Check Engine light was on.

My car has 112340 miles.
My car has an automatic transmission.

The codes mean you need a camshaft position sensor (or something related to it such as wiring). Typically you replace the camshaft and crankshaft position sensor as a pair.

The jerking/misfire sounds like you need a tune-up at 112k miles. Spark plugs and wires should have been replaced around 80k to 100k miles. You may also need an ignition coil.

Driving with the misfire can damage other items including your catalytic converter and other parts which would keep your engine from accelerating. I recommend having your stalling issue checked and Check Engine Light diagnosed as soon as possible to prevent further damage.

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