96 Cavalier, problem with stalling, specific to warmer weather

My 1996 Cavalier has been stalling in warm weather for the past couple years, but each year it gets worse. I actually had to get it towed yesterday(AAA is a wonderful thing!) when it stalled and wouldn't stay running for more than a minute. It knocked, but only when we pushed it pretty hard, because we were stuck in an intersection. The engine is not overheating, not smoking or anything like that, but the check engine light comes on after it stalls and will stay on for days or weeks. It will stall wheter the AC is on or not, I tested that too. I keep up on oil changes, and used Engine Restore on it as well. The Fuel Filter has been replaced, I originally thought that was the problem.

Any help would be great, I'd love to get her running strong again, I don't want to have to buy a crappy car from the auction!

Read the DTC codes, that'll get you pointed in the right direction. What did you do to the engine before this happened? Changed the plugs?

I bought it used in 2005 with a headgasket about to go, and it did within 2 weeks. That was replaced, the car was tuned up, and all the usual maintenance done. The only big thing done since then has been the fuel filter. The only other problem I had was a blown fuse for the horn. It didn't start stalling until the summer of '06, and so far it has only stalled when I drive it a lot in a few hour period. I have to wait until my mechanic is available to run a diagnostic.

Like I said go to a local auto parts and have them read the codes. They'll do it for free. :)

I should be able to get it to the Auto Zone near me, I can do that tomorrow probably. Thanks, I didn't know I could get it done there for free!(my mechanic is my uncle, so he always does my work for the cost of parts, so I just usually go to him first)

Turns out it was the O2 sensor, and it's something I can replace myself! I hope to get many more years out of this little car!

Thanks for your help, I might never have known to just go to AutoZone, and I'm a procrastinator, so imagine where it woulda gone! :p

Thats great! Do yourself a favor and get the O2 sensor removal socket kit(most AP's will rent it free just leave a deposit) depending on where the sensor is located it can be a lifesaver.

Toyota cavalier 2.4 stalling problem is maybe a design fault.
A small hose, going from the resonator box to the oil separator, maybe a major cause of the cavalier2.4 stalling problems. The resonator box sits above the air intake, its part of the black plate above the throttle (nearest the radiator)
The resonator box is attached to the throttle body and also has a little spout with a small hose attached which goes to the oil separator. This hose is suppose to suck the fumes from the crankcase back into the air intake and so back through the combustion cycle. This car requires the crankcase to have a vacuum. Presumable so that hot oil fumes do not affect the cam and crankcase sensors. (these are major sensors and not cheap)
So that hose needs good airflow, but…unbelievingly, this hose has a build in kink or buckle so as to make it easier to fit in place. Close examination show that just above the buckle the hose is softer and easy to further depress so as to close it right off. The air suction might not close it right off but most probably reduces the air flow considerable
I have replaced that hose with a strong reinforced hot water hose and cut exactly the right length so as enable to shape it in a fair curve without buckle or kink and yes for some days now, although I am still a bit nervy driving it, I have put the car through some good testing and not one warning light or stall (so far)
I'll be happy if this would help some of you with a same problem
Don't forget the spark plug gap, .060'' or 1.5mm or just slightly less