mzeitlin

I am getting a P303 code - "cylinder 3 misfire".
My 2000 ES300 has 71,000 miles on it. I have never changed the spark plugs.

Before I change the plugs out - is there anything else I should consider?

The car is running rough - it is intermittent and I get a different smell out the exhaust (fuel injector is fine?)

Where is cylinder 3? and for that matter, I can't even see the spark plugs?

Thanks

JSM1284

Cylinder #3 is the middle cylinder on the back side of the engine. Check the Plug as well as the coil. You need a very small hand to remove the coil, the plug sits down the plug tube in the head. You will not be able to see it. Or you could remove the intake manifold for easier access.

mzeitlin

Thanks JSM !!

I am believing it's the coil. I have never had a spark plug go bad on me and I smell gas out the exhaust indicating the injector is working (my guess).
I may give it a shot to get at it or else have it repaired.

JSM1284

NOTE: "Cold" and "Hot" in these sentences express the temperature of the coils themselves. "Cold" is from -10 °C (14 °F) to 50 °C (122 °F) and "Hot" is from 50 °C (122 °F) to 100 °C (212 °F) .



1. INSPECT SPARK TEST
Check that the spark occurs.

Remove the ignition coils (with igniters).
Remove the spark plugs.
Install the spark plug to the ignition coil, and connect the ignition coil connector.
Ground the spark plug.
See it spark occurs while engine is being cranked. NOTE: To prevent gasoline from being injected from injectors during this test, crank the engine for no more than 5-10 seconds at time.

19psi

i'm betting on a coil.

mzeitlin

Getting to the number 3 cylinder is near impossible unless you are 10 years old. I can't get a 10mm socket on the nut and hold it.

Taking off the intake manifold looks like a lot of work. The engine removal hook is bolted onto it and to the block along with a ton of other connectors.

Unless I can find someone with small hands, I'll have to spend some dollars taking it to the shop for what is a simple problem.

Damn how it couldn't be the cylinder in the front!! Figures.

JSM1284

Try going up from under the car.

mzeitlin

A final update on the misfire:

I replaced the Cylinder 3 Igniter for $54.00 and the problem is solved.
Car runs great as normal.

I was able to get a 10mm wrench on the nut from driver side fender, but barely.And I used a flat head screwdriver and silicon grease to disconnect the wire harness. Took 30 minutes to figure out - took 2 seconds to repeat. Not that bad.

The new part is identical to the OEM (case anyway) Denso case. I was surprised at the lower cost compared with Bosch, Borg Warner, etc. No matter - it works.

On the side:
I assume the cylinder is carbon'd up since gas was being injected with no combustion. This was only the case for about 10 miles of drive time after the igniter failed. The smell out the tailpipe during failure was foul smelling (not quite like the rotten egg smell) - the smell now is clean - and it was immediate after the igniter was replaced and the engine was run for 5 minutes.
Any way - check engine codes were cleared and have not shown up since. Problem solved.

Thanks!

JSM1284

Congrats! Great job!