I drive a 00 civic si with 94k mi.I recently (8k mi) ago did a tune up new dizzy, spark plugs, wires, timing belt, water pump, new cam seals, all new belts fresh oil change car was running great the vtec crossedover loud and pulled excellant.. But just recently car hasnt been feeling the same vtec dosnt react the same so i did a fresh oil change thinking it would fix it but still nothing.. Vtec still comes in but its not noticable at all, sometimes cant even tell if it engauged. Does anyone have any ideas what to check???

 

Also i Have no cel

 

You might just be getting use to the power. Compression test?

 

hmmm idk felt like before i could hear it alot more in 2nd and 3rd now not so much.. I did a comepression test about 3months ago mybe it was close too 200 or at all across

 

there could be like 99943 reasons why.
clogged cat? usualy you would get a cel for o2 sensor though.
improper oil pressure? (oil pump/not enough oil, etc) vtec sux if oil presure aint right

 

wouldnt the oil light come on also if oil pressure isnt correct??

 

my 2000 si acted the same way when i had the b16a2 in there.
some days it ran hella good other days really slow.
no idea why

 

....sometimes..
the vtec selnoid can burn out and not throw a light.
the vtec module can be clogged with nasty sludge.
try taking that off and cleaning the screen.

 

Butt meter is not a good gauge. If you really want to know I would suggest putting it on a dyno then you will know if you are making normal power or not. My sti doesnt feel as fast as I "remember" but I have a motorcycle now to which is way quicker

 

Im thinking a need a oil pump when i start the car and its idling i can hear roaring/whirring/whinning sounds but i dont want to throw parts at it any way to check it??

 

also i notice my valvetrain ticking louder than normal like its not getting enough oil

 

run a oil pressure gauge and check out the readings