Question: how do you know if your car needs a fuel injector?
Answer: The Engine Misfires. Dirty fuel injectors may cause your vehicle's engine to misfire. ... 
Idling Gets Rough. Does your vehicle sputter and shake when you're at a stop sign or sitting in traffic? ... 
Your Gas Mileage Tanks. ... 
The RPM Needle Starts to Dance. ... 
Your Car Won't Start.