Thread: Driveability issues when car is warm?

Update, replaced the CTS today. Same issue. Car runs great cold, when it warms up it starts to misfire, and the issue gets worse and worse. Fan still turns on with the key in the on position. Replace ECU maybe? Gonna go ahead and replace the spark plugs with known good ones, brb.

Why didn't you test the CTS per the FSM before replacing?

You could try replacing the ECU, or you could start doing the FSM diagnostics.

The FSM doesn't mention the CTS in the list of steps to determine hesitation when engine is hot.

Re-did ground from engine block to chassis and it seems to have helped... still have hesitation on light throttle after car has warmed up. WOT above 4k or so is absolutely flawless with no hiccups or stumbling. First/second gear around 2-3k is the worst for the stumbling.

Tps maybe. My car did the something like that. I swapped the tps and it was fine

MAF is what it seems like to me. Check your voltage there.