Odd running problem please HELP

[Ni$$@n240]

Sometimes when I drive the sr it acts like the ignition is dropping one or two or all cylinders. It starts and drives daily but cruising in town at 30mph or after driving awhile and starting it back up it seems to misfire? When this happens the car jerks violently. I think the problem is heat related because it wont do it when the engine bay is cool. Almost acts like the intercooler piping popped off. Any helpful advice would be appreciated.
The problem occured even before the ecu was tuned.
It has the Q45 ignitor
Need to get a new maf because the one on it has been siliconed but has always worked.

[PyR0NiAk]

Coolant sensor = cheapest and most likely

[CRyan]

Coolant sensor = cheapest and most likely

Second that.

[Ni$$@n240]

Oh thanks guys didnt think of that. Come to think of that had to replace one on my dads ka but it didnt miss as bad as the sr is. Anyways I will try that thank you.