do ignition coil brands matter? seen different brands for different prices. i have codes p0300 p0301 p0303 and p0304 which are misfires. i use to have p0302 also but i switched out the ignition coil for that cyl and thats the only one that isnt misfiring now.

anyway i want to know if it matter which ignition coils i get for my 2005 tc. 82k miles. what are the differences and will CEL light/codes come back if its not oem brand

 

Keep with stock ignition coils, they will work out the best for you. If you are having misifres on all 4 cylinders then my guess is the issue lies deeper then coils.

 

Thats what i was thinking. I had a mechanic take a look at it and he swapped out the 2nd ignition coil. He shut off my CEL. After about 50 miles they came back but this time i didnt have a misfire in cylinder number 2 anymore. But still have the random misfire, and cyls 1,3 and 4 are misfiring. I just ordered an ignition coil from trdsparks.com if that stops another misfire then i will order the other 2 coils. I was also thinking All the coils went bad and have been bad for a while but the computer wansnt telling me. I swapped out my catalytic converter about 2k miles ago and it was really burnt up. The misfires may have caused that. Thats why i think it has been misfiring for a while

 

what brand were these other ignition coils you bought? need to know so we all stay away from that brand, in case you find out that was what was the cause.

and yes the misfires could have definitely messed up your catalytic converter, no doubt.

 

Sounds like something other than a problem with the coils, do you have oem plugs installed? I would also recommend to use the factory oem brand since going aftermarket usually only last a short time. If it comes down to all of the coils being bad i have a lightly used set for sale

 

what do you think can cause ALL my cylinders to be misfiring? i already tried switching the coils and still no luck. i got OEM ones

 

Do you have any mod's done to the car?

 

just an exhaust. magnaflow with custom piping. and i replaced my catalytic converter cuz it went bad. 2 days later after the exhaust and cat install my CEL light came on with the misfire codes. but i doubt that can cause that. or is it possible?

 

I would start off next with possibly doing a compression test. Changing the exhaust out wouldnt have anything to do with a missfire as far as i know, also you may want to check for any vacuum leaks

 

do i gotta take it to someone to do it? or what would i need to do it my self?

 

You can do the test at home. You need a compression tester. You remove a spark plug (or all 4) and screw the unit into one of the spark plug threads.
These are possibly the least expensive models. They probably work fine.

http://www.harborfreight.com/compres...kit-66216.html

http://www.harborfreight.com/quick-c...ter-95187.html