Hi everyone,

I hope somebody here will be able to help me


Mods: cheap SRI / 4-1 H / de-cat / greddy evo2 cat back exhaust

I have a problem with my 6g 99’ b16a2. After I have changed the headers to stainless 4-1 and put a de-cat the car has lost throttle response on low revs.
I don’t know much about cars, but I presume that the air fuel maps should be adjusted after those changes. Unfortunately I don’t know a place where this can be done.

Can somebody tell me please how can I increase this without changing back to OEM. Would a CAI do the trick ? Apparently the CAI acts negatively on the throttle response comparing to a SRI…. (?)

Thanks a lot !
( sorry for my English )

 

you lost back pressure, and low end power.

and yes a cai slows throttle response, but not to much. Is your timing right?

 

Does your car idle properly? Double check that all the vacuum lines are hooked back up properly. That's all I got

 

This is definitely worth looking into. Use a timing gun and don't forget to jump the service connector during the procedure.

Have you tried to retrieve CEL codes from the ECU? Is the primary O2 sensor working? Is there an exhaust leak from the gasket of the new header?

 

Well, since you have an OBD-II system (assuming the b16 not the vti version and is also OBD-II compliant). Are you still using the factory locations for the primary and secondary oxygen sensors? Are you plugging the hole for the secondary with a dummy plug? If so, then you will have a bad throttle response due to the fact that they are used to adjust the fuel/air mixture according to the exhaust output. Are you throwing a CEL? Has this just recently happened when you installed the header? Has your timing slightly slipped?

 

what? what ya talking about??

 

thanks for all replies !!!! much appreciated

as suggested I will check the timing and CEL. There are no leaks from the gasket of the new header.



it is a VTi. Yes, I'm still using the factory locations. Should I move the o2 sensor closer to the throttle body ?

Thanks again !

 

There is no throttle body heated oxygen sensor.

 

To me it just sounds like you've moved your power band into the higher RPMs, probably increasing max horsepower, but losing your low and mid-range torque. If it's really considerably less, then start looking for mechanical issues.

 

sorry, I meant throttle sensor (lambda sensor ?)

I thought that you meant mowing the lambda sensor closer to throttle body, so when it opens the air will suck harder (for the sensor) just by the throttle body opening, and the sensor will read this a bit different (higher loaded) ...

I believe that they have been moved a bit with the new header. Should I move them somewhere closer or further from the cat/header ?