just about two days ago when vtec kicks in its very loud and doesnt pull as hard as it use to....car runs great and idles perfect but just when it kicks in its loud and wont pull that much..does any one knows what this could be?

 

any ideas of what could it be???? my friend told me it was because the low oil checked and the oil was low but i bought more....took it for a drive and still very loud once i hit the 5600 rpm's

 

i had that problem long time ago. My car had a short ram intake and an axleback. The problem ended up being a really clogged cat. Changed the cat and gained a lot of power. Vtec was not as loud anymore either.

 

Timing is not set correct. Maybe timing belt skipped a tooth or so.

 

+1

 

my vote for a exhaust problem.

 

thanks guys ima take the car to an exhaust place tomorrow...kus i been hearing some rattling in the exhaust so hopefully is my cat....good opportunity to upgrade to a hi-flow cat

 

my vote is distributor going out or timing off

 

What? No. You all think that a clogged cat.converter can rob a lot of power? I disagree. 5 horsepower is not alot. Vtec is supposed to produce 30 hp on the H22. I mean it has to be clogged with some obstruction in order to block major exhaust flow, but come on guys.

OP, are you hitting Vtec on a cold motor? It has to reach operating temps before ECU activates Vtec function. Check Vtec solenoid, clean screen, any CEL ?

 

I have seen the honeycomb come apart and lodge itself in the exhaust, causing the car to have a very hard time starting, stalling, and barely being able to go 60mph. So yes, a clogged or failed cat can cause these symptoms.

 

it was a clogged cat...need a new one

 

i'll buy the the bad one for 55 if you ship it to me

 

where you at ZIp code?

 

Weird... I just replaced the car on my prelude. What's with the stock prelude cTs not lasting?

 

dont sell it for 55. take it to a scrap yard and get 80 for it lol.

 

really thats how much its worth?

 

Actually I lost 35whp with the clogged cat.
The motor made 115whp on the dyno which is how i found out that something was terribly wrong. This was at a prelude dyno day meet which preludes were average around 140whp.
Ended up being the cat. So it was way more then 5hp. And i don't THINK a clogged cat can rob a lot of power. I KNOW it does. Where do you even come up with 5hp? Do you even know how VTEC works? The reason why VTEC makes "30hp" is because of the extra flow it is getting so if you restrict it even more. Then it's not gonna do ****.

 

your timing belt keeps your camshafts in time with your crankshaft to operate properly, and since your motor is DOHC you have an intake camshaft and an exhaust camshaft. your exhaust cam jumped forward one tooth on the timing belt, and now you are experiencing the effects of it.

to confirm that this is the problem, your going to hafta take off the valve cover, and the upper timing cover. then your two cam gears will have an "up" arrow in each of them, and two lines. your need to spin the motor until the two lines point to each other, and the up arrows should point straight up. if you're not able to line these up, it's cuz your motor is outta time.

fortunately if it's only one tooth, you can simply take off the timing belt, align everything again, put it back on, and your motor should be perfect.

 

The OP already said it was a clogged cat.

 

Hmmm, my dyno figure was very low too (100w kW). I am able to remove my cat all together where I live (not needed once a car is beyond 15years of age). Is a straight pipe (matched with exhaust dimentions) or a resonator better for power?

 

I love how people think that they already know the problem beyond a doubt hahaha. The more feasible causes were clogged exhaust or possibly valve lash as well. OP, did the new cat bring your power back all the way??