I have a 99 si. my alternator went out a little over a month ago, and i changed it, no big deal. but the thing is, ever since i changed that,a couple things went out. Speed sensor and map sensor. i changed the speed sensor with one off another tranny we had layin around, it works (its from a d tranny) and then changed out the map sensor, that worked. but even though i got all the codes gone, except the one i have for the O2 sensor in the cat, since i don't have a cat, and the guy that i bought the car from cut the sensor off. But here is the problem. My vtec doenst engage like it use to. Before, it was a very noticeable change in sound and power. it was decent. but after all that **** happened, not it doenst engage very hard at all. once the car is warmed up, it engages at 5500rpm, every time. you can hear it, but its not as loud, and you cant feel it at all. its like only the sound change, nothing else. the whole car feels slower than it did before. i have tried checking and changing the vtec sol. and that never did anything. i have an oil pressure gauge, it reads 65 (is that right?). i have enough oil in there. i really dont know what would have caused the change. It worked perfect before..anyway's, enough ranting....im lost, can anyone help ???

 

you are NOT supposed to be able to feel it change. HUGE misconseption about VTEC y0!

 

this wont help with the sensors or the sound but does your new alternator turn freely?? because it might be possible that you have more load from that which might cause a loss of power??? thats all i can think of, hope it helps.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DirtySol &raquo;</TD></TR><TR><TD CLASS="quote">you are NOT supposed to be able to feel it change. HUGE misconseption about VTEC y0!</TD></TR></TABLE>. i belive you about not being able to feel the vtec but what is the purpose of it if there is no noticable power gain???

 

Honda engineers designed it to be a smooth transition. The effect wasn't intended to be a sudden intense pull. It raises the power band, so our cars can still be efficient at low rpm's, while having a high rpm power band.

 

the only reason i say i cant feel it is because i use to be able to before, and the car ran a bit faster, and now i cant feel it and its slower

 

Do a compression test and see if thats all ok.