i went and got a test pipe and eliminated the bottle neck on my Tanabe piping today and my car feels very weird than before...the shop made a 2.5 inch straight pipe from the header to the S-pipe....after the install, i test drove it and i felt more restriction than with the stock cat and Tanabe bottleneck...when vtec kicks in around 6k-8k i feel alot of restriction...my car is an OBD2 so the CEL light is currently on...Can someone please tell me why he sudden lost of power?

 

CEL being on makes car run like ****. Makes it run rich and retards timing is what i have heard. You should have two o2 sensors your car being a 98. Have the o2 sensor nearest the motor bunged in and then just ziptie the other one to the chassis where its safe. This is what i have heard you have to do in order to have no cel with a test pipe. If im wrong someone please correct me. Good Luck.

 

probably cause uh...when ur CEL is on, your car runs at 75% of it's actual.

 

take the O2 sensor and wrap it in aluminum foil, and tuck it away or duct tape it to the bottom of the car, and close the bung with a bolt or something, your CEL will go away. right now it thinks your cat is malfunctioned and its throwing a CEL which makes u run like ****..once that CEL goes away your good to go. That O2 sensor that im talking about (the secondary one) is just for detection of the cat condition, it basically there to make sure u have a cat thats working properly.. Leave the one thats in the lower portion of the header alone, thats the primary O2 sensor

 

with that CEL on it will run like ****. my friend had all this **** on his civic, but broke his o2 sensor while doing his header install and just plugged the hole with a bolt.

it ran slower than an automatic civic.

 

thanks for the quick replys...i found out that one wire was loose from the clip on the o2 sensor thats why it was throwing a code 41...i fixed that this morning and have been driving around pretty hard...check light never came on again but i still run like ****....hella restriction from 6k-8k...is it because my tanabe muffler is not letting enough air out?

 

Did you reset the ECU? Maybe there is a soft code still stuck in there.

Pull the 15A ECU fuse in the engine compartment box, wait 30sec, replace.

Quick. Free. Worth a try.

GL

EDIT: As a last resort, you might consider a secondary O2 simulator. You can probably find one for $25-30 if you hunt around.


Modified by OBD1Kenobe at 12:28 AM 10/1/2004

 

well i put in the stock setup back on and resetted the ecu by unplugging the harness from the ecu...car is still weak and restrictive during high RPMs...ill try to take out the ecu fuse to see if that works....also even with the test pipe on...i never threw a CEL...

 

So your exhaust piping goes from stock header to 2.5" piping to 2.36" piping to Tanabe muffler? I didn't get much info so I'm just guessing.

 

DC 4-2-1 to 2.5 piping to 2.36 tanabe piping and muffler...i think...???

 

Like others have said reset the ECU. Also check for exhaust leaks.

For those who claim that the CEL will cause your car to run like ****. The code 67 (catalyst system efficiency below threshold) normally associated with running a test pipe has no effect on engine tuning, it is there to monitor the health of the cat. I have been running with my CEL on with code 67 for 6 months now in my '98 GSR and no decrease in performance.

Other codes may have an effect but generalizing CEL's with putting cars into limp mode is not correct.

 

i resetted my ecu with all the differents kinds of ways that i knew...now the feel of vtec is not felt whatsoever anymore..VAFC will say its on vtec but nuttin happens...can it be my primary o2 sensor? does the primary o2 sensor have anything to do with vtec engagement?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98B18C1 &raquo;</TD></TR><TR><TD CLASS="quote">i resetted my ecu with all the differents kinds of ways that i knew...now the feel of vtec is not felt whatsoever anymore..VAFC will say its on vtec but nuttin happens...can it be my primary o2 sensor? does the primary o2 sensor have anything to do with vtec engagement?</TD></TR></TABLE>

Maybe nothing is really wrong and that's the way it is. I remember when I changed exhausts from my Tanabe SRM to my GReddy EVO, I couldn't hear or "feel" VTEC anymore. My butt dyno was telling me my car felt slower and weaker with the GReddy EVO exhaust. I reset the ECU plenty of times, I changed my o2 sensor, fuel filter, spark plugs and spark plug wires and it wasn't helping at all. I took my car to the track and I ran the same exact 1/4 mile times that I ran with my Tanabe exhaust.

After a month or so, I switched my GReddy EVO exhaust back to my Tanabe SRM exhaust and I could finally hear or "feel" VTEC once again. The car felt more powerful and faster but in reality it was my mind & body telling me that even though the car didn't really gain any power at all. I don't know if this is what's happening with your teg but I just thought I'd share my experience.

 

i even took out my muffler to try to hear vtec but didnt hear anything...now my o2 sensor is messed up and im running LEAN like a ****...can it be the vtec solenoid cause i dont hear a click when it hits vtec? or can it be something is clogged?

 

If you couldn't hear VTEC with your muffler off then there's something wrong. Since you are running lean, it could be caused by a number of things but they usually don't affect VTEC engaging unless your ECU is running in limp mode. I'm not sure what's wrong but maybe you are right about the solenoid.

 

alrite i have talked to other people who had the same exact problem as i did and they said that it was the o2 sensor because that cause the ECU to like crap....so ill get a new o2 sensor and well see if that solves the problem. Thanks for the help people.

 

Good luck man. Those o2 sensors are not cheap.

 

u need to convert to obd 1 buddy cause u will burn the **** out of ur second o2 sensor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98B18C1 &raquo;</TD></TR><TR><TD CLASS="quote">alrite i have talked to other people who had the same exact problem as i did and they said that it was the o2 sensor because that cause the ECU to like crap....so ill get a new o2 sensor and well see if that solves the problem. Thanks for the help people.</TD></TR></TABLE>

Those people are feeding you misinformation. At wide open throttle (WOT) your GS-R goes into open loop mode so it ignores the O2 sensor. ECU just runs the WOT map which is pretty rich.

In my GS-r I cannot feel the VTEC crossover, exhaust just goes a little raspy @4400RPM. Secondary cross-over of the intake manifold is audible @5600RPM.

Simple way to test if you have VTEC still there... adjust you VTEC crossover higher. Say 6000RPM, should feel a kick in the *** ...do you feel the VTACK now?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsr-2nr &raquo;</TD></TR><TR><TD CLASS="quote">u need to convert to obd 1 buddy cause u will burn the **** out of ur second o2 sensor</TD></TR></TABLE>

Second O2 sensor is the same design as the primary O2, so if the primary O2 is content so will the secondary. Switching to OBD1 will only get rid of the check engine light.

 

xactly

 

alrite guys...i couldnt stand not having vtec so i took my car to Justin from Sinister Motorsports so he can take a look at it...it turned out that my VAFC was messed up and wasnt sending a signal to the ecu in order to open up the solenoid...soon to find out that the VAFC wires were kinda spliced near the controller and the 12 volt signal wire was touching the ground wire...so he separated the wires so it wont touch and now everything works fine...i can feel my VVVTTTTTEEECCCCC now....Thanks alot to Justin at Sinister Motorsports... good guy and does some bad *** engine work ...also thanks to all the H-T member who helped me