You might need to change your throttle position sensor.
your control module is bad
try cleaning the egr valve passage and egr valve.
it could be the idle speed sensor located on throttle body however i replaced mine and it still idles high. The code indicates lean air/gas mixture so i am still looking for small vacumm leak
?ignition control module/pickup
The clutch on a 98 cav. is hydrolic and has no adjustment. If still full of fluid "brake fluid"needs replaced.
If it only happens when you're in gear, maybe your torque converter isn't unlocking and is causing it to stall at a stop.
my 05' cavalier has a bad alternator problem its charging the battery a little bit then stops and the little power my battery has is drained by the end of the night. I replaced the alternator twice and the battery but still no difference.
Did you replace /check the seats also?
clean iac sensor and o ring
had the same problem with a sibring,took to the garage,they replaced the thermostat and gasket and found a hairline crack in the thermostat housing they replaced the housing and everything was fine then
When the EGR valve goes bad, it circulates very rich mixture back through the intake. You most likely have fouled spark plugs.
control valvue ( relay ) internal on Gas control valvue is not switching, replace gas control valvue, By:Joe Draw1.com