Misfires, code ps300 to 306

TASHA IDLEBIRD

MEMBER
2002 TOYOTA AVALON
3.0L
V6
AUTOMATIC
177,689 MILES

I changed all six spark plugs it worked for two days now it is back doing the same. Not catching after start and shutting off. Got codes ps300 to 306 then cylinder 123 misfires. Will changing the coil packs help? Or just the fuel injectors as suggested? But during my visit a customer said check the oil it is probably throwing o2 sensor codes and others because it is low on oil. One he was right I had no oil and two after putting oil it still does it. After waiting three hours for it to cool down and start which it did not I had to drive home like the Flintstones with both feet accelerator and brake at the same dangerous time.

I want to change all coil packs. What you think?

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning.

No, the oil has no connection to the issue at all.

The first thing I would do before changing anything is check the fuel pressure. Low fuel pressure will cause the 300 code as it indicates not enough fuel being delivered to the injectors for firing the cylinders with the proper amount of fuel.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Beyond that, it could be the coils or injectors but I would check the fuel pressure first to be sure it is not the fuel pump.

Coil failure will be all the time. The engine will not run fine one minute and bad the next time.

Roy

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