I just bought a black '03 T4R 4.7 V8 SR5 with 110,000 mi and I am fixing it up for my son. I just Seafoamed it, changed the oil to Mobile 1, put on some Nitto Crossteks, tinted the windows, and did the Turtle Wax Black Box treatment and it looks like new. I bought NGK Laser Iridium spark plugs and was going to change them but I began wondering if I should change the ignition coils. I looked online and saw a price variance from $23 -$77 dollars each for the coils. Here is my question: How often do the coils need to be replaced? A second question is are there any recommended brand of coils or any brands or parts suppliers to be wary of quality issues? Do you only replace the coils just when there is a problem or is there a benefit to replacing them at time or mileage intervals ? Thank you in advance. I am not sure if they have been replaced before but doing it at the time of the spark plug change would be ideal, although I would hate to have to drop $500-$600 on 8 high priced coils if the less expensive ones will do.

 

There is really no reason to replace the coils unless there is a problem with them. Your oem Toyota ones will be better than any aftermarket coil.

 

Thank you. I left them in place and it runs great with the new laser iridium plugs.