2002 trailblazer runs very rough. cam postion sensor was changed but still geting check engine light changed sensor because of code what would you check

Bad coolant temp sensor or EGR valve stuck. You can remove and test temp sensor (the one for the ECM--has only one wire) using cold and then hot water and read resistance with ohm meter.

First try cleaning the throttle body,make sure you take it off the intake manifold so that the rear side gets cleaned as well. While doing the cleaning, disconnect the battery so that the PCM will reset and relearn to the freshly cleaned throttle body.

Give me some more information about this problem. May be i can help.

Possibly the O2 Sensor or the Cam position sensor or the plug wires themselves.

Oil pressure switch is bad.

dammed electronics ,bane of my life so your not the only one and in cases like this i can only suggest you bite the bullet and take vehicle to a main dealer .sorry i know this isnt the answer your looking for but from experiance certain things on modern motors you cannot do your self

Clean throttle body first, make sure you disconnect battery foe about 30 minutes so PCM can relearn to cleaned throttle body.

beleive it or not changing the oil if dirty will solve this code, also found that connector gets oil in it and that also makes p1345 code turn on, open connector and look for oil in it,look at sensor and actuator plugs for oil,the main plug connector is the actuator plug it fills with oil and makes contact between pins setting p1345 code, hope this helps.

Do you know if the plugs were changed, a bad or broken plug will also cause rough idle and slow acceleration?

I replaced the Cam Shaft Sensor. I also cleaned the Throttle Body with carb cleaner. I had my wife hold down the accelerator, while running I sprayed down the throttle plate and the entire area around it. Now my TB finally idles smoothly, and it hasn't died yet!! Check engine light is gone and I passed the emissions test!! Yea!!!