89 Reves up when started

Good day everyone.. I have a 89 S10 that is right now the RPMs are high after starting and will not die down even after shifting into gear...I have changed computer pieces that 3 mechanics said it was and it still is not fixed I have also looked over the vacuum seals and hoses and they are all sealed and clamped .thanks in advance kennjr

Sounds like the Idle Air Control (IAC) valve is sticking open.

i have replaced the IAC part and now the check engine light is flashing the code is for Oxygen according to the book any idea

What code number are you getting?

the code is code 13