Corolla shuddering

Have a 2001 Corolla with 150k miles on it. It isn’t straight up dying, but it is shuddering when driving at slower speeds or while stopped at a stop light. Have had the air intake looked at so that shouldn’t be it. Sometimes the lights on the dash will dim when this happens but not sure if it might be a battery issue or that is just happening because the car is dying.

Are you getting a check engine light?

The lights on the dash will dim if the engine rpm gets too low. But that could be a cause too. Since it is easy enough to check the battery and charging system, that’s where I’d start if I had this problem on my Corolla. First off, just try cleaning the re-tightening the battery connections maybe.

Is your Corolla an automatic or manual?

Corolla’s of that vintage I think have what is called an idle air control valve. It performs the same function as the choke, to control the idle speed in the various situations. That part can fail or more likely get gummed up with gunk. If you had the intake looked it, an inspection of that park would usually be part of that inspection. But ask to make sure.

Air/fuel mixture problems and ignition system problems are another possibility. What’s the situation with the routine maintenance as suggested in the owner’s manual? Everything up to date and current?

Yes, have a check engine light and I think that is for the catalytic converter. I’ve driven it the past couple of days, but haven’t noticed anything unusual, however it seems to happen to my wife on a more regular basis. I’m more of a careful driver, so I’m wondering if that doesn’t have anything to do with it.

I think she kept things up-to-date when the car was newer, but has kind of let it go the past few years. It also leaks oil, so we thought that might have been the issue at first.

First the engine problems have nothing to do with careful driving or not. Second doubtful that oil leak has any bearing on problem. (assuming you are monitoring oil level ) Third have the codes read by AutoZone (free in most states) and post them here to receive better advice.