times up, the long version.
I would replace them , they are designed as throw away repair items*, and it seems you might already be experiencing low voltage with the intermittent signals you describe.
This is a startlingly old thread but it did get you where you wanted to go. I might replace one as they fail, if they were fairly new, but yours are not. Most people accept a lithium battery life is about ten years.
Get it all done at once, chalk it up to safety maintenance, and move on to better things. I was just last week quoted sixty bucks each at america's tire on a c5. I was looking at a wheel and tire package, the sensors were regular price. i would think freshness of the batteries would be the main concern when buying the device. I would check the build date before closing the deal, trying to get something fresh.
It is not an uncommon device today. Any tire shop can hook you up and program the receptor on your car, which must identify the signal from each wheel.
My research on these deals only covered the C5, here it is . For a while, the oem and aftermarket all came from the same place. Then, as the market expanded over time dorman came in with a different looking part.
Dorman makes a lot of generic stuff, manifolds to window cranks. With demand comes supply , they probably come from all over the place today.
I am not qualified to give tips on which part is better for you, but having customers come back is a major driver of profit loss in any shop, so I don't think you would have to worry about bunk parts from a shop unless you got counterfeit merchandise. Or, if you buy the cheapest thing you can find on the internet , the batteries are probably where the costs were cut.
Personally I am planning on getting my C5 sensor set from tire rack , mainly because I have some tire rack script from a charity shelby auto event but also because they probably turn the stock over quickly, I probably wouldn't have age concerns. But would inquire about age. My car is getting old C5 tressure sensors aren't flying off the shelves today. Plus, the last time I checked they had the same builder as chevy, and I try to support guys who give back to the hobby.
I try to save a little coin by buying the same part without the GM logo, if the situation is reasonable.
While I am not qualified to give the parts advice you asked for, I can pass advice on.
I went to a corvette event at the petersen auto museum where they had one local guy and two brothers out of Texas , all respected experts. They were talking from a restorers viewpoint, but I thought the advice well worth considering for a street car. They advised " always buy factory parts unless cost is an objection".
They cited the extensive development of the factory parts , the durability testing needed to prevent recalls, etc Gm has a lot more invested, and to lose, with a bad part. Plus they fit better into the systems they were developed for. ( i once had an old jag that preferred only champion spark plugs , a well documented eccentricity for their old straight six. I never made any sense of it, even to this day i am somewhat puzzled but results are results )
As restorers they also had to keep an eye on resale value . It is a lot easier to value a car with all Gm parts to a buyer.
I know that concern well. I once, when I was young and the cars were cheap, passed on a red Jag xke convertible with tan interior , the desirable body kind, because it had a cheap pep boys alarm under the hood. I figured the car had been run on the cheap, and it scared me off. You don't forget passing on a car like that . At the time I didn't know how durable those cars are, I just knew I didn't have a lot of funds to invest in a bad buying decision.
* today the pressure sensors are just another type of valve stem, but some guys tear them down and rebuild them with new batteries. Some guys enjoy that stuff. They post about how to renew the part, tear down, soldering batteries, epoxy, the whole bit.
Good knowledge if the part ever goes obsolete .