Whats Wrong With My Car?

[GXE10]

hi i drive is200 auto

after accelerating and the engine rev up to 3000rpm+ crusing at around

100km/h

i take my foot is off the gas but the rev still stay up at around 2500rpm

usually it drop back down to 1000rpm after i take off my foot from the gas

i try resetting the ECU and cleaning the throttle body, its still the same.

some ppl tell me it must be something wrong with my intake. is this true? or

is it something wrong with my exhaust?

[Rodders_UK]

Do the revs drop if you knock the stick into neutral?

[GXE10]

yes if i push it to N, it go back down to 800rpm

[Rodders_UK]

Sounds like everything's normal to me - what makes you think there's a problem?

[GXE10]

usually when i take my foot off the gas, the rev will come down to around 900-1500rpm

but now........... the engine rev at the crusing speed rev

[Rodders_UK]

That's what it's supposed to do