casias

iTrader: (1)

I have an Dakota that I swapped with an LY6 from a 2007 Sierra over 10 years ago. In those days, I had it go to Current Performance and he reworked the original truck harness and connected it in my truck.

Many years later, I am now experiencing some electrical glitches in the harness, and also switch to an LS3 intake which looks ugly with the dirty Sierra harness lying on it.

I bought a replacement harness, but the O2 sensor connectors on it are male trapezoid, and the O2 sensors in the truck are male trapezoid. WTF? When I search, it seems some years GM had male trapezoid on the sensor, and in other years, female. I know I will have to change either the harness to female or new O2 sensors with the female connector.

BUT WHY?

Anyone know why GM did this?

Thanks!

cobra30689

While I don't have the exact reason WHY.....I do see where the difference lies. Starting in 2008 there was a unique RPO code combination on the 6.0 (called ZW9) that featured the trapezoidal connector. Best definition of ZW9 I could come up with on the interwebz is a pickup box delete/upfitter option. What that has to do with the O2 sensors, who knows. The 5th pin is not used. By 2011, ALL 6.0's had the trapezoidal connector, regardless of the ZW9 RPO code. Smaller engines retained the traditional connector.

Haggar

Usually simply to eliminate the chance of mis-plugging something in the assembly plant.

A ton of design decisions that people don't understand are for plant quality, and have no function in the design itself. When I do line reviews, I literally try to break every step in our plants. Find every possible way an operator can screw up at a station. You don't want an operator swapping pre and post cat O2 sensors.

krav84

This is definitely perplexing ! im having a similar problem. My 2002 avalanche vortec 5.3 came with flat 4 pin connectors on harness and my y-pipe came from a 99 silverado im told which has square 4 pin connnectors.
i researched this and found usa/mexico used one kind of connector and canada made trucks used the other connector type
napa ans amazon.ca have flat 4 pin connectors they say will fit for 96 and 124 canadian plus taxes.
amazon.com has 4 pin flat connectors that look like will fit for 37 usd plus taxes, customs, shipping.
that same model searched on amazon.ca says it will not fit my engine.
theres also 4 sensor sets for 125 cdn on amazon.ca that will fit.
just seems like im destined to pay 125 cdn to get one sensor that i am not even confident wont throw a trouble code anyways.

is there a easy way to wire up case grounded Flat sensors to non case grounded harnesses?