I searched through the forums looking for an answer however was not able to. My car runs okay through the city, however, once I jump on the highway it feels like I have no power! I'm unable to rev past 4000 rpm and can't go past 70 mph. I'm always the slowest driver even though I floor the pedal.

It first had trouble going up hills on the highway, then gradually the problem got worse to what it is now.

-98 civic ex stock with k&n short ram
-no cel
-swapped out the atalytic converter, didn't work
-swapped out dizzy, didn't work
-swapped out spark plugs & wires, didn't work

Plus whenever I hit 4,000 rpm, there's a loud windy-like flapping noise coming from the engine. Any other suggestions?

 

same problem here with d15b vtec wont go past d15b and constant whining noise like a choke valve stuck shut. check engine light suggests map sensor throttle position sensor and idol control valve, limp mode mine wont go past 35 can barely get to school.

 

put oil in it

somebody help him out

 

finalclassic: First make sure your CEL lights up when the fuel pump primes. Check your MAP sensor signal voltage after the engine has completely warmed up to normal operating temperature. Post the RPM and the voltage. You should also borrow a fuel pressure gauge from a parts store and check your fuel pressure with and without the regulator vacuum hose attached. It wouldn't hurt to check the grounds as well.

Flat92: If you have codes for those three components, check the wiring and make sure that each of them connect to the correct pins on the ECU and that all of their ground wires are well grounded.