A little bakground, car was in an accident at high speed possibly in VTEC. hit a deer front end damaged, last o2 sensor was ripped out.

after a year of sitting and getting fixed up. its back on the road and vtec doesnt work. i replaced the vtec sol. assembly and got a used o2 sensor last week a little stonger but still nothing.. and i get 250mile to a tank. so thats a problem too. no check engine light so the o2 sensor should be good.

car has an intake and evo2 catback so i should be able to hear vtec.


any suggestions??

 

the ep doesnt have the vtec your thinkin it does... The A3 has i-vtec.. i was explained as it kinda being on all the time.. There isnt a certain rpm that vtec turns on.. like the b18c5, k20z.. we got screwed bud.. There may be more info in the FAQ;s about this... Hope this helps

 

i-Vtec engages at 2200rpm. It's for fuel economy, not horsepower.

Stop being a ricer.

 

how do you know your single intake vtec isn't engaging?

Also, just because there is no CEL doesn't mean the O2 isn't bad...

 

this motor is still slow so i dont know how u will notice if vtec works or not . the vtec is as weak as a d16 SOHC vtec motor. hopefully your not running any vtec piggybacks like a vafc. i know i had one on a base rsx i owned years ago and it went bad and wouldn't engage vtec. once i uninstalled it and vtec was back. with no CEL maybe check to see if the bulbs not broke or blown or just hook up a scanner anyway and see if anything comes back for codes.

 

i dont think its working because before i hit the deer i remember it being louder and somewhere around 4500 rpm I thought vtec kicked in. i have a type S and u can really hear it after 4500rpm.


if i hooked it up to a scanner would it say the o2 sensor was bad? i heard form a friend vtec wouldnt kick in if the o2 ssensor is bad. true?

CEL works it was on better i up the o2 sensor in and turned off by it self.

 

in your OP you mention it was the secondary 02 sensor, behind the cat. this will not effect Vtec engagement.

 

if i remember it correctly its in the front part of the cat.. havent had time to get it scanned yet but hopefully friday.

 

Its like the question that every ep3 owner has in the beginning haha

Went i bought my ep i didin't know either, i have ask a honda dealer guys and he told me i was suppose to hear the vtec lol

 

the vtec on the type s and the vtec on the si are completely different. the si basically only has a lift increase on one valve per cylinder. there are no changes on the exhaust side. as where the type s has valve lift increase on all four valves per cylinder. also, the type s has 50 degrees of cam advance, as where the si only has 30 degree. so, you wont have that sudden grunt in power (or noise) that you have in your type s. honestly, i think that you haven't driven the si in so long, youve become jaded by the power and difference of your type s.

now, for those who say i-vtec is solely for fuel economy, you're and idiot. now, i will admit, the lift part of the k20a3 is about worthless. but the tq and horsepower gained the variable cam angles is significant.

need proof? my 03 si w/jackson racing supercharger is currently throwing the check light for a cam angle sensor. soo, no vtec... at first, i didnt think the difference would really effect performance. WRONG! i took it to my old work to toss it on the dyno, it is about 35whp down on power in the lower rpm. but, the power up top is still within about 9whp. as how that would effect fuel MPG, if your car is dog slow, you're more likely to drive it harder to accelerate as you desire. usually using more throttle/fuel, so i guess in a way, that could be perceived as being for fuel mileage. me personally, such a huge increase in hp and tq with cam advance isnt specifically designed for MPG, its just an added perk.

 

...or it's running rich as heck/timing is off and bogging?
^^;

 

ef9civicgen4.. i think ur right after putting some miles on it. and changing the spark plugs it seem to be running normal.