my question to everybody is my dads 2005 sle fully warmed up idling in gear idle goes as low as 450 rpm. still manages to maintain slow idle without stalling or shaking or anything. is this normal because my 2003 sle doesnt do this. what could cause this? no codes, has a new upstream 02 sensor, cleaned throttle body and new iac motor.

You can check your PCV, EGR, and throttle position sensor. Are you sure it'* really idling that low? The tachometer may not be reading correctly. 450 rpm is really low. I run about 750 in the summer and that seems low.

well no im not sure if its really idling that low. but the tach shows normal speed when compared to mine when cold started and idling in park. it just goes down when its been running and is fully warmed up and idling in gear. i checked pcv its clean and rattles when you shake it. egr shows no sign of sticking or improper flow. i havent checked tps though. what can i do other than bang on it and see if idle surges. do you think its possible i have a low signal from the maf even though i cleaned it with maf cleaner? this is just weird cause other than this, the car has no drivability issues.

Try this test for your TPS.

I wouldn't be too concerned, as long as the car runs well it trys to idle as low as possible to save gas and your gauge might just be off since they are a reference at best and are no way totally accurate