car wont rev past 6500 RPMS

[ferruccimike]

i have a 1999 honda civic si. mods are hks exhaust. custom headers (4-1) which are dented. also have spectre intake (i know its not the best). and skunk 2 coilovers. no power steering and no AC. my problem is throught all gears i can only rev up to 6500 rpms. vtec still kicks in a 5500 rpms. trying to figure out why i cant rev to 8k. when i first got it i could rev to 8k. ive owned it for about 8 months now. just found out that my o2 sensor is lose before the cat. could it be the sensor? thanks! also my piston rings are worn. stock b16a2. stock ecu. i actually reved to 8k last week. like sometimes i can and sometimes i cant. most times i cant tho. also saw that one of the three wires are not connected to the o2 sensor. thinking its a ground wire. its the sensor after the cat.

 

[XpL0d3r]

You've pretty much answered your own question. Get new rings and fix your o2 sensors.

 

[ferruccimike]

yea but the rings have been bad since the day i got it and it just started doing it like a month ago.. both the o2 sensor and rings..

 

[XpL0d3r]

They probably got worse from not being repaired right away. It's like a crack in a windshield -- if you don't fix it, overtime that crack is going to get worse.

You know there's a problem with the rings and o2 sensors, and you'll need to fix them anyways, so why not start there and fix those?

 

[ferruccimike]

true.. i mean i plan on fixing them when i have time. already have the parts to fix my rings. but i have to order my o2 sensor. what do you recommend for the o2 sensor?

 

[CHILD]

If you have a stock ecu, vtec does not engage at 5500 rpm in a 1999 si. Worn piston rings won't stop it from revving, the car will gladly let you destroy it. What is happening at 6500rpm? Bogging, feel like a fuel cut? Loss of power?

 

[ferruccimike]

no.. its like its hitting its rev limiter. i mean i guess i have no idea if i have a stock ecu then. i thought vtec engadges at 5500 rpms????

 

[Marco Alfaro]

I'm having the same problem with my 97 civic ej6 with an F20b swap, short ram intake, speed daddy exhaust, S300, and I'm not sure what brand coilovers. I don't have a hard time starting it up but I can't get over 4,000 RPMs in park, neutral, or in drive, haven't tried reverse but don't need to, I haven't done anything to try to fix it because I don't know where to start. So far this info is the first Iv heard on it so thanks, I'll try those things and see what I get!