I think so. The air fuel mix is affected by the abiilty of air to pass through the filter. If the a/f mix is upset and the engine control module doesn't have enough range to compensate, it will cause the engine to run with odd parameters and that would likely affect the exhaust and engine mechanicals such as knock.

That said, while I'm not familiar with the 2000 trouble code management system, I believe the CEL will normally stay on for several driving cycles after a fault is corrected, unless the code is manually deleted before. In other words, if you drove in with the light on, and only the filter was changed, the light would not necessarily go out on the first start-up thereafter. Be interesting (and indeed a very positive sign) if it remains off for good.

You might want to have the memorized codes read, and cleared, just to start off with a clean slate.

 

If your air filter was dirty enough to set off your O2 sensors then a new air filter should give you a noticeable improvement in power and gas mileage. Please let us know how it goes.

 

Short answer, yes

Long answer ... since you don't know anything about cars, it probably wouldn't make any sense anyway.

I would tend to agree that it's odd that the code went off immediately but ... works for me.

Keep up on the maintenance, learn to at least check all the fluids and read up on common issues and signs to avert potential expensive repairs with a little prevention.

Here's a pretty basic tutorial of how engines work.

HowStuffWorks "How Car Engines Work"

 

All right, I finally had a few minutes to call the shop that did the maintenance and ask them about it. They said they would never reset a CEL unless they specifically discussed it with the customer first.

It's been off since Thursday night. I haven't put too much mileage on it since then, but I can't remember the last time it stayed off for more than two days.

 

I can't discount the possibility that the O2 sensor CEL goes off as soon as the fault is corrected, although this isn't the case with my 07. However, as long as the CEL light is working (that is, is not burned out and comes on when the key is in the ON position but engine is not started), and the car is running well, then take it as a good sign and enjoy.

p.s. This could also stand as a lesson regarding the value of following the recommended maintenance schedule, which includes inspecting/replacing the engine air filter periodically.