O2 sensor

I have a 2000 GP SE and recently had the code come up for the front O2 sensor. I replaced the sensor and cleared the code. I only had that one code. My check engine light just recently came on again. It's the same code again for the front O2 sensor again. I'm taking the car in tomorrow to have it diagnosed further, but was wondering if anyone has any ideas as to what would cause the same code again. Car is running fine and getting great mileage. Ideas?

Had a guy on here a while back with a similar situation. His turned out to be a damaged wire to the O2 sensor.

ya that would be my geuss also an exposed wire or fault wire

IF you didn't buy an AC-Delco sensor, that's probably what's wrong. Bosch oxygen sensors are junk, I used to sell them when I worked at Advance Auto Parts, and we got back a ton of them as defective, especially the mulit-lead heated ones.

I appreciate all the advice. I did put in an AC-Delco sensor. Turns out not its not the sensor but a number of things. Seems the front of the intake manifold is leaking and it needs a tune-up. I can handle both, but would like some advice on things to watch for. I've done intake manifolds before, so am familiar with how to do them for the most part, but it has been a number of years since the last one. What specific to the 3.1 should I be aware of? I heard mention of there being two different types of intakes for the J series 3.1. Any advice would be greatly appreciative.

your 2000 has the 2nd design, with the push rod guide plates on the gasket, fel-pro part # ms90562.
You'll need valve cover gaskets, fel-pro vs50442, and an egr mount gasket, fel-pro 70804 to complete the job. Since you'll have the throttle body out of the way, you might as well replace the oil pump drive seal, fel pro 70800 while you are there, as these are prone to leak on GM 60 degree v-6's and are easy to do with the upper intake out of the way. Make sure you take the valve covers off and clean the muck out of them, and change the pcv valve, delco part # cv892c while you're in there. Make sure you use threadlock on all the bolts and torque everything to spec. And make sure all gasket mating surfaces are spotlessly clean, and you won't have to do it again.

your 2000 has the 2nd design, with the push rod guide plates on the gasket, fel-pro part # ms90562.
You'll need valve cover gaskets, fel-pro vs50442, and an egr mount gasket, fel-pro 70804 to complete the job. Since you'll have the throttle body out of the way, you might as well replace the oil pump drive seal, fel pro 70800 while you are there, as these are prone to leak on GM 60 degree v-6's and are easy to do with the upper intake out of the way. Make sure you take the valve covers off and clean the muck out of them, and change the pcv valve, delco part # cv892c while you're in there. Make sure you use threadlock on all the bolts and torque everything to spec. And make sure all gasket mating surfaces are spotlessly clean, and you won't have to do it again.

Dont forget the Orings for the heater hose tube and the bypass tube. Must have an inch pound torque wrench and according to GM new bolts for the lower intake. They have a specific threadlocker patch for this. I reused the old bolts with loctite. Just clean the heck out of them. I used the GM gaskets for the intake, new design released for the leak problem. P/N 89017279 includes the upper and lower intake gaskets.