Does any one know if the O2 sensor connectors on my truck are oval or square for the front/back/passenger/driver. I have an O2 sensor on the passenger side using a square connector and the O2 sensor on the driver side is using an oval connector for my catless headers. Reason I am asking is I think the shop that did my header install may have mixed the front and back on either side and I cant find my other 2 connectors that used to monitor my cats. I figured they would have taped them up some where out of the way but i think the ones they are using are mixed up. I was getting no reading on the passenger side when I went to go do my dyno tune and when I ordered replacements for both fronts, the replacements are both oval connectors.

-thanks in advance

 

Just changed the fronts on my truck. Both driver and passenger side ones are oval for the front O2s, square for both of the rear O2s

 

so that must be why im getting no reading on the passenger side, when the shop did the header swap with out cats, the must have plugged the rear where the front should have been. Now I have to find the front plug that I hope they didnt just cut it off.
-thank you