4 O2 sensors

[merc68]

Does a 2002 GMC Sonoma use 2 P/N 13193 up-stream sensors AND 2 P/N 15703 down-stream sensors, or
4 sensors of the same part number? And if I only need 4 pieces of 1 part number, which do I go with
thanks

 

[greg409]

you don't mention which engine you have, my '98 v6 has (2) upstream b/4 the cat converter and (1) downstream after the cat.

a 4cyl would have (1) b/4 & (1) after


luck,greg

 

[lmleck]

My 03 has 4.3l with 2 before cat and 1 after, all same number.
I just ordered 2 each Delphi ES20319 replacements. Upstream
I had put in Bosch, but my mileage has suffered, and I then read of similar occurrences comparing Bosch to Delphi or Delco.