Kik

2005 tC auto. Well I've been searching around and I can't find an answer to my question SO hopefully you guys will answer for me.

If the Cylinders on the car ar 1,2,3,4 from the belt side, but the firing order is 1,3,4,2 And the code reader is putting out a code of p0303 (misfire on Cyl 3) then which cylinder is this code referring to? The physical number 3 cylinder or the firing order? So I guess I'm asking, should I be looking at cylinder #2 or #3 physically on the engine? I pulled the plugs already and they are not tan but a whitish gray color. I do not get heavy with the gas pedal so I know it's not from heavy acceleration. When I start the car it sounds like it's missing pretty bad but if I let it warm a little then it runs well the missing is almost completely done but the is a little roughness to the idle. My reader is pulling p0303 / p0303P and an NA code. Any help is appreciated. Thanks.

sciontc_mich

most likely the misfire is from a faulty ignition coil pack. That's the black thing the spark plug connects to. You could swap the cyl 3 coil pack with another pack and that code would swap cylinders, also checking the coil packs with a multimeter would verify it's bad. I'd have to dig into the service manual which I don't have here where I am right now, but there are some multimeter tests.

and to answer your question, it's the physical cyl #3 you need to look at. The firing order is just that, the order in which it fires off the physical cylinder. first #1, then #3, then #4 and then #2.

a new ignition coil pack is most likely what you need..
rockauto.com has the Denso brand which is what's in there it's only $59, try and compare that to the dealer prices, you'll laugh your butt off at what the dealer wants!

here's the part number DENSO Part # 6731307 $59.79. That price has dropped I remember them being more like $80-100.. thanks! now I know if mine goes I'll know where I'm going to get one! oh yeah just checked, trdsparks.com (dealer online) has the toyota one for $80. Up to you how much you want to spend, I'd go for the $59 one.

Kik

Thanks for the reply, I switched coil pack #2 with #3, it still runs a little rough but I'm not getting that misfire code now. I did get a code after starting the engine about the 3rd time but it cam up as N/A on my code reader. I cleared that code and I haven't had another one in the last 8 starts. When it gets a little warmer out, I'm going to replace all the coil packs and the plugs. I seen on the Rock auto site that I can get 4 coils (igniters) for around $70. Probably cheap stuff but it'll get me through the testing phase of finding out what's wrong and then I can put quality parts on.