My '99 Blazer with 4.3 and Automatic with 130,000 is hesitating. When the
scanner is hooked up while driving it reads that the engine is shifting
from 1st, 2nd, 3rd, and 4th in the first couple of seconds basically before
the engine ever gets to 1500 RPM's. So it acts like a hesitation problem
though the actual problem is that it is shifting way to early. This happens
about 50% of the time. Everything is fine if I manually shift the vehicle.
SES light is on and the code is "secondary air injection". My mechanic
doesn't think this is related.
Recently changed plug wires, cap, rotor, fuel filter. Checked the EGR
valve, and found and reattached a disconnected vacuum line though nothing
has fixed the problem
Any help would be great.