I have a d15b non vtec swaped on my 2000 civic ex stock P2P ecu and it wont pass 5200 rpm i have already clean the iac and raplace the air filter so my question is, is it the ecu that isnt reciving the vtec or couldirt be the spark plugs or cables?

 

Get the correct ecu. The p2p is looking for sensors that your engine doesn't have. The issue is there really isn't a usdm option unless you use a P2E ands use the 3 wire iacv throttle body. This is all assuming your car is a 5 speed. If you can convert to obd1 you might have some more options. What intake manifold are you using?