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I bought a used 05 ss/sc 2.0 about 2 months ago. It drove fine on the test drive and the drive home(about 50 miles). When i started it the next day it wouldn't start until the 3rd time I cranked it over. This is when the p0017 code first appeared, it did this a few times over the next 3 weeks until it finally wouldn't start at all. I replaced the camshaft position sensor, the crankshaft position sensor, reset the timing chain and ran a compression test.

Cylinder 2 had low compression, leakdown test showed loss on the cylinder. Pulled the engine and replaced the rings(one of them was installed upside down. Had the cylinder walls de-glazed and honed, also had the head resurfaced.
I replaced the timing chain and a number of broken timing/balance chain guides.

I finished rebuilding the engine, got it installed and cranked it. It started right up without hesitation and ran for about 5 minutes. I shut the engine off and cranked it again, the same issue reappeared. P0017 is back, doesn't want to start. I unhooked the battery and re attached it, it started again without issue. Shut it off and try again, wont start.

Im clueless at this point and any help will be greatly appreciated. If any other information is needed i will post anything i can.
 

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P0017 Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation - PCM

Sounds like you need to do the Crankshaft Position sensor relearn if it was never done. Sometimes a new sensor will work without a relearn, it will start on the first crank but that's it.

Once you get a re-learn through full RPMs it should be fine.

Did you try pushing it to high revs after starting it? Sometimes this will give enough data for the PCM to go by.
 

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P0017 Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation - PCM

Sounds like you need to do the Crankshaft Position sensor relearn if it was never done. Sometimes a new sensor will work without a relearn, it will start on the first crank but that's it.

Once you get a re-learn through full RPMs it should be fine.

Did you try pushing it to high revs after starting it? Sometimes this will give enough data for the PCM to go by.
I have not done a re-learn, ill have to send it out to have that done.(no tech ii scanner)

So i messed up, I mis-timed the camshaft position sensor after the rebuild, forgot to line up the timing mark(i think it was about 2AM).
With the timing mark in the correct position the engine will now start without much hesitation, but the P0017 code is still present, even after clearing, and unplugging the battery for an extended period.

I really don't want to rev it high, due to it just being rebuilt. I was gonna keep it under 4k RPM for the first 500 miles.
 

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The relearn process has you put it to the floor until it hits rev limiter, then you back off. Some Cobalts will re-learn by themselves over a period of time and re-starts so maybe wait a week or so to see.
 
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