92 S10 Blazer Code45

Car has been sputtering under acceleration. pilled a code of 45, What are the chances that itis actualy just the o2 sensor. Where is it located and how many would there be. The car has 117,000 mi. and I have owned it for 3 years and have never changed it.

I have had this exact same issue. Sometime it runs fine but not always, right?? Code 45 is the barometric pressure sensor circuit or the egr valve. Good chance it is the egr valve and it is carbon'ed up. I had mine off of it was sticking open. Be careful what you use to clean it though...Harsh cleaners can damage the internal plastics...