PO303/300 Missfires

[Big-Boy]

Hello,

I have a 1997 4runner SR5 5-speed.

I've had a check engine light going for some time due to my charcoal canister, but haven't worried about it.

However, recently, the check engine light has started flashing here and there. I seem to have less power under 2k RPMs than I used to.

I am getting a PO303 and PO300 code. I tried replacing all the spark plugs but still having the issue. Should I mess with replacing the coil packs and cables and hope that it's as simple as that, or am I probably looking at a bigger issue here?

Thanks for any info/comments!

 

[Bad Luck]

Hello,

I have a 1997 4runner SR5 5-speed.

I've had a check engine light going for some time due to my charcoal canister, but haven't worried about it.

However, recently, the check engine light has started flashing here and there. I seem to have less power under 2k RPMs than I used to.

I am getting a PO303 and PO300 code. I tried replacing all the spark plugs but still having the issue. Should I mess with replacing the coil packs and cables and hope that it's as simple as that, or am I probably looking at a bigger issue here?

Thanks for any info/comments!

If you haven't done spark plug wires in the last 40k miles then it wouldn't be a bad idea. Before you go replacing coil packs try swapping cylinder 3 coil pack with one of the other two and see if your misfire moves. Cylinder 3 coil pack is the middle cylinder on the passenger side. Here's a good thread with spark plug/wire/coil pack information and spark plug wire routing: Spark Plugs Wires and Coil Information for the 5VZ-FE

If you are still getting a cylinder 3 misfire then I always do a compression test next followed by a cylinder leakage test on any low compression cylinders. You can rent a compression and leak down tester from most auto parts stores.

If your compression is good across the board then I would suspect a bad injector for cylinder #3.

 

[jgue467]

... check engine light has started flashing here and there. ...

Flashing CEL is 'puter trying to tell driver to let Off the throttle as much as possible. Misfire is allowing way too much unburnt fuel threw exhaust, too long of this begins to damage cats, not to mention strain on engine.

I'd also suggest wire replacement, most likely the one tied to cylinder 3 but all would be much better. Luck and enjoy the runner.

 

[spartacus]

Ohm out the injectors 13.8 ohms st 68* give or take a couple.