Cranshaft Position sensor problems
 

I have a 98' blazer 4x4 with a 4.3l v6. My check engine light was on so I had it checked and it come back crankshaft position sensor. I bought a new one and replaced it and the light is still on. The only real problems im noticing is at 50 mph and up it has a hard miss. On cold days it boggs when stopped. I check my old and new cps for any contact wear but didnt see any. Im lost any ideas would be great.

What code(s) are causing your SES light to be on? Are you aware that you need to do a crankshaft sensor relearn when you replace or even disturb the crank sensor? Crank sensor isn't going to cause a hard miss on a particular cylinder. If you have a felt miss, then you have at least a P030X code turning on your light - but after replacing the crank sensor, the misfire detection is probably screwed up also. You will need to get your own scan tool and do some reading in order to even ask the right questions here and obtain any help. Autozone reading your codes and advising which parts to replace isn't going to work.

Cheap and capable scan tool for Android. Under $30 total. https://blazerforum.com/forum/2nd-ge...-retard-90496/

Note will not do crankshaft sensor relearn. Software or scanner to do that will cost you at least $350. No, Autozone and the parts store scanners cannot do it either. So you are stuck paying $$$ for a shop to do it at some point, in addition to the price of the crank sensor (which it seems you didn't need in any case).

Once you obtain your current codes, read about them here and then you will be ready to ask your questions. Know that most any valid answer given in this forum will involve using a scan tool repeatedly to aid in diagnosis.
https://blazerforum.com/forum/diagno...codes-dtcs-49/

Sorry, but them's the facts!