Engine miss

P0304 is a misfire code !. Of course it trigger the knock sensor code too becuz of uneven cylinder power balancing. Any cars and I mean any cars thats over 50K miles in order to keep it in shape. Car owner spend average $800 - $ 1200 per year just to keep up the maintainence. Thats not including repair. Timing belt water pump, brakes, alternator, starter are part of the wearing tearing items as maintainence.I spend around $600 for every1 of my cars. My toyota has 223K miles on it and I never have to fix it. And I make a living working on cars only. To give u some idea whats happening on ur car.I need more info. To step by step fix ur car. Chances are very slim.2000 and up newer car require much more high tech equipments, training and experience. Not as simple as swaping parts. Msg me if u wanna continue

Thanks for replying. I finally got a diagnosis. They say its either fuel related or ignition. One mechanic says I need to replace the fuel injector to the tune of about $500. Another poured a half bottle of injector cleaner into my half tank of gas and said to drive it out and if the missing doesn't stop to come back and see him. He says I have no compresdsion problem and he could hear the fuel pump click or tick ( not sure whick one he said) when he pressed the accelator from under the hood.
I want to be sure it is the fuel injector before I spend money on it and that its not the coil as was the case with my sister's F350 truck. She got the coil replaced but later her engine light came back on though the missing had cleared up.

My van only seems to miss when I put it in drive. Idling in park, it doesn't sound like it's missing but the minute I put it in drive or reverse, the missing or rough rotation magnifies. When I give it gas it sounds like its missing and the engine light flashes sometimes. When that happens I feel vibration but when the engine light stops flashing, the vibration ebbs a bit. I can get up to 60-65 MPH. Sometimes it rides smoother than other times. I have been riding the bus to avoid driving until I get it fixed because I am afraid this might damage something else in the engine.

By the way I won't be working on the van myself because I'm female and don't know the slightest thing about engine combustion. However, I'm learning. It was your website that motivated me to get the timing belt changed. I freaked out when when I read what could happen if it broke. I hadn't changed it at all and I was at 127,000 miles!

I will make a donation to your website in the future but right now, I'm trying to get my vehicle running so I can get off the bus and into my van to get to daily radiation treatments.

I don't want to get taken by the repair shops though. That's why I'm seeking advice, especially after spending $764.00!

Any guidance would be deeply appreciated.

U are probably 1 outta 20 female car owner that really care and not chosing the denial atitude.. Any problem can be proof and verify. It's always how much it cost to find out. Any maybe are specualtion. When some1 take ur money and conduct legitament auto diagnostic test. They gotta stand behind their word --> cuz they took ur money. We are the only profession which always under recognize by public.A doctor send a patient to the lab. Bill all kinda test. Or even wrong diagnostic the 1st few times still normal. But a mechanic gotta be right on the money for free the 1st time. I sometimes wonder I gotta be one arrogant, eccentric and stubborn idiot to still hang on to this profession. I sign up on this site becuz it allow me to see more cases to sharpen my diagnostic skill. But I still haven't get pay yet. Just a pure male chauvenist egotistical pride. But what really make me stay here is to solve more diagnostic problem to proof to myself. John wayne do this. So am i. Heeee hawwww