Hello everyone, I would like to thank you for your time.

I have a 2000 4runner limited rwd 5vz-fe

I was driving with a broken airboot allowing unmetered air in.

While driving with the broken boot, I noticed my engine turning fast and slow, again and again until i heard metal slapping and it shut off. (broke the engine mount) (replaced) I fixed the air boot and the engine throws a p0301.

The engine vibrates under 5mph and at braking as well.

I changed the injector, coil pack, timing belt/tensioner, spark plugs & wires, IAC Valve, TPS sensor, all vacuum leaks, all exhaust leaks, o2 sensor bank 1 and 2, checked ECU voltage, changed Coolant temp sensor, MAF sensor, valve cover gaskets and I feel less vibration yet still getting the same misfire(just less severe)

The misfire feels like a surging. The surging can be felt in the brakes when braking under 5-6 mph and only when accelerating under 10mph. The cat makes a louder clicking noise now but the cat is still working.

I am at a loss of words. Sometimes the problem goes away at start, then after a little gas its back.

 

Not only unmetered air but all kinds of interesting other things as well .

You might want to do a compression check on cylinder # 1

You are still getting the same PO301 code ??

What did the number one spark plug look like ??

All these parts you replaced had failed ?? You did check them??

 

My spark plug was dented on one of 2 grounds and the electrode not to be found. replaced all spark plugs injector on 1 and coil pack on 1