1995 1.6 mazda mx3

Sorry...HP does not come cheap. You have the basics you can do to get you started and you'll feel gains. BUT..it gets expensive after that. 1st add a cold air intake, that is the least expensive mod you can make. Then go for a computer upgrade, that will cost several hundred but by far the most bang for the buck. After that, do a complete exhaust revision. Header, high-flow cat converter, larger mid tube and low restriction muffler. At this point, you've invested at least a grand and with luck gotten another 20 horsepower. After this, it get more expensive.

i've already installed a cold air intake,& cleaned the cat out . so all i need for the exhaust is a header , larger mid tube , & a low restriction muffler then my exhaust system will be done ??? So where should i look for the computer & header???

Alan, I hope you didn't "GUT" the converter? If you did, you're gonna have problems. I would check with Summit Racing, JEGS and finally NOPI. Nopi will have everything you need but will likely cost more. When you decide which products are best for you. Write down the item number and shop them around online. The computer upgrade, I'd start at JET electronics. The header you'll have numerous choices. Also, consider heat wrapping the header. Good luck!