Just replace 6 spark plugs myself, a first timer. Start the car after, engine misfire and shakes, engine light is on, got a 0201 code, Ignition Signal Circuit. What's wrong? Please help.
Car ran ok before I replaced spark plugs.

 

are you sure you plugged in all of the coils? when doing cylinder 5, did you remove everything in the way or try to bend the coil out?

 

if u bent the coil on one of the back plugs then u broke it, u MUST take the two bolts holding the IACV assembly and get clear access to the coil. if u did not its a good chance u broke the coil, and thats expensive.

lets hope not so here is another scenario: when u put the coils back on make sure they are on ALL the way and the screws that hold the coils are screwed in flush to the surface, otherwise the coil will not have good contact with the plug.

did u touch anything else in the engine at the time ?

 

If you shake a broken coil, can you hear spring like noise? I think I might have broken the cylinder 5 one, because I did remember bending a little when pulling it out. Darn...

 

u got it, thats your problem, i would try to diagnose if thats the exact coil tho,

i think, but im not sure, u can swap the coil with another one from the same bank( front with front and back with back) and see if the engine light tells u now that u have a different cylinder missfiring. if u do then thats ur coil, if not then i might be wrong, i hope someone corrects me if i am wrong

 

Man, hard lessen learned. thought I read enough posts and tutorial on how to do this. Didn't know should've been careful with the coil. sigh... so much effort trying to save couple of bucks, down the drain. That's really discouraging.

 

that is not the IACV you have to move. It is a part of the EVAP assembly. secondly, all coilst rattle. even good ones. See if you can get your hand on one rear coil used and replace cylinder 5. If you cant get it cheap, then diagnose it first since there is no need to waste money on a coil that isnt bad.

 

thanx for correcting me i was not 100 % sure, but the two bolts still needed to be removed in order to not bend the coil

2da mizzax : can he not swap the faulty coil with one of his own coils from the same side to determine if thats the actual coil thats broken ?

 

you can swap it, but the problem is that you have to drive long enough for it to throw a code. It wont let you know right away (not necessarily). You can also have the car idling and unplug the coils 1 by 1 and plug it back in. only problem is a rough idle will only get so much rougher so you have to pay close attention to feel the difference.

 

Now I am having a second thought on this. I only bent the coil slightly, because I did move aside the stuff above the cylinder 5. I didn't touch anything else, and I checked all the wires and harnesses, all seem fine. How fragile is the coil? Will a slight bent break it? I might have to buy a coil to see it can fix the problem as I can't get a cheap one right away.

 

I know it would be kind of a pita, but did you inspect all the plugs well before intalling them? Could be a bad plug too possibly. Making sure all electrical connections are snapped back in properly. Could be a coil gone bad or broken in the process as others have stated, but eliminate the easy stuff first before buying a new coil. Maybe recheck the plugs to make sure none cracked or have a bent node or something? I know that when I did my plugs for the first time a couple months ago I had to disconnect some stuff to get to the back coils. Did you do the same and forget to reconnect something? Get the coils pushed back on the plugs securely?

I'm sure you rechecked everything after the problem occured, but sometimes in the midst of our irritation/anger/frustration with a problem occuring we forget the easy stuff. Good luck.

 

Thank you guys for all your input. I went through all the coils this morning, and found out bank 1(?) coil, the most left one in the rear, has one bent connector pin. It was bent upwards. I used a flathead screwdriver to level it with the other two pin and put it back in. Now everything seems ok, and I reset the ECU.
Thank you all for your help!

 

congrats....

 

thanks mizzax, you are a big help everytime.