88 g20 left bank o2 sensor is it upstream or downstream

What is your question?

5.0 l 305 v8 1988 G20 ...obd1 code 44 lean mixture is left bank sensor....so what do I buy? An upstream or downstream replacement part?also where is it located? And if you know what size is the sensor supposed to be as in the mm length

What makes this problem better or worse?

Worse at cold start better After run for a while sometimes

How long has your 1990 Chevrolet G20 had this problem?

Since I found the throttle body gasket was ripped and cleaned body and gasket and put it back