i changed the plugs and o2 sensor, i don't have any engine code now it drive better but still no performance, my friend have a dx hatch with a 4speed also but his is stock,i have bolt on and his car accelerate faster then mine.

 

My car does pretty much the same thing...When I shift into any gear it always jumps like i'm not giving it enough gas. So, it could be my spark plugs or my injectors need to be cleaned?

I know my fuel lines were dirty and the shop I had it in cleaned it out/fixed it, but I'll run a gas treatment/injector cleaner through it and let you guys know how that went...after that, should I look into changing the spark plugs? How can I look at them and tell they're bad?

 

You should invest in a Chiltons Manual for your car. You can find them at any pep boys/autozone or car stores like them. They have pictures of what your spark plugs are supposed to look like and what they're not supposed to look like. They can also help you fix the most common problems like the one you are having.

 

i find out why my car is like this, before i change the motor it had a d15b2 in it but now i have a d15b1 and the intake manifolds are different. the b1 throttle doesn't open all the way at wide open throttle.