97 C1500 w/codes PO339 and 341

[driver540]

Have a 97 Chevy C1500 with 4.3 manual tranny. Had put new timing chain in and afterwards have codes PO339 and PO341. Have changed every sensor on this darn thing and tuned up twice. Will run for about 15 min. then start runnin rough and die. Will give PO341 everytime even after cleared and sometimes PO339 is given too. Any thoughts?

[777stickman]

P0339 is for the crank sensor (CKP) Sensor Circuit Intermittent.. P0341 is for the cam sensor (CMP) Sensor Performance.

After reading thru the diagnostics for both of these codes I would suspect something with the CKP since you were in there changing the timing chain.

1. Chipped or damaged reluctor wheel
2. Incorrect reluctor wheel
3. Incorrect alignment of the CKP to the reluctor wheel


Also if the CKP was removed and/or replaced the CKP System Variation Learn Procedure needs to be performed. This requires a high end scan tool in the hands of a knowledgeable technician.

Let us know how it goes.

[j cAT]

Originally Posted by driver540

Have a 97 Chevy C1500 with 4.3 manual tranny. Had put new timing chain in and afterwards have codes PO339 and PO341. Have changed every sensor on this darn thing and tuned up twice. Will run for about 15 min. then start runnin rough and die. Will give PO341 everytime even after cleared and sometimes PO339 is given too. Any thoughts?

I have seen the crank sensors fail after getting heated ...remove the sensor and measure the resistance cold then heat it up to 212 deg f ..see if it holds the same resistance ..

if the sensor had been installed wrong or a damaged reluctor this would always cause your problem ...same with the connector ,,,but still on something this old could be anything ..