Dear Tom and Ray:

I have a Dodge Durango, 2000, four-wheel-drive. I have three faulty oxygen sensors (as detected by a scan); one of them may have oil-soaked wires. I'd like to replace them but have been told by a mechanic friend that I really ought to get actual Dodge parts from the dealer, because "Dodges don't like aftermarket parts from O'Reilly's, Advanced, etc., auto parts stores." An auto rebuilder friend of mine says that's a bunch of nonsense, and that the aftermarket parts from O'Reilly's, et al. are just fine. There's a significant price difference, and I'm reluctant to ask Dodge about this, as I know what the answer will be. So, what do you think? Original factory oxygen sensors, or aftermarket, more affordable ones?

-- Steve

RAY: There's no single easy answer to this question about factory parts versus aftermarket parts.

TOM: Lots of aftermarket parts are just fine. In fact, some are exactly the same as the original parts, and are made by the same supplier. We've run into cases where the original supplier is, for instance, DENSO, and the same DENSO part is available online cheaper than at the dealer's parts department.

RAY: But it's also possible to get cheap junk. We've had situations where aftermarket parts didn't perform the way they were supposed to.

TOM: In this case, Steve, I think it's fine to take a chance on aftermarket parts. Why? Because the labor is so minimal. An oxygen sensor is basically a plug-in part. It takes a minute to install (although wrestling out an old, rusted one might take a while!).

RAY: So if, by chance, the part you get doesn't do its job, you can unplug it, take it back for a refund and buy something else. Because aftermarket parts usually are guaranteed.

TOM: It's just that the labor is not. So if you were installing a clutch that took a weekend of labor, you wouldn't want to mess around with aftermarket parts unless you were really certain of them, because that's not a job you want to do twice, even if the second set of parts doesn't cost you anything.

RAY: But in the case of things that are relatively easy to install and remove, especially on an older vehicle, I wouldn't hesitate to try a well-regarded aftermarket part.