I just want to write this to put down for posterity for others to be able
to find what I couldn't find on my own but with my friends' help, I was
able to solve the problem.
The 1998 Toyota 4 cylinder has over 100,000 miles on the original four NGK
BKR5EYA plugs & four wires & two coils & (how many?) fuel injectors.
Last week, the yellow emission-control OBDII Check Engine Light lit solid
(not blinking so it wasn't that serious) and a friend checked it this
weekend to tell me the code is P0301 misfire detected, P0303 cylinder 2 of
4. I had noticed the engine running a bit roughly under acceleration for
about a month but I wasn't sure what the cause was.
I called Toyota this morning and they said plugs and wires would not fix
this cylinder-misfire diagnostic code and the Toyota 4Runner needed to be
brought to them for service because it could be the ignition system, the
200-dollar fuel injectors, the 100-dollar ignition coils, the fuel system,
the EGR system, the engine congtrol module computer, etc. They were clear
that just replacing the plugs and wires would not solve the problem. I
needed an 800-dollar diagnostic service.
Undeterred, my kind friend bought four new two-dollar ND K16R-U spark
plugs, gapped them to 0.031 inches and torqued them to 14 foot pounds in
the Toyota 3RZFE 2.7 liter 4-cylinder engine. Unfortunately he also had to
replace the 50-dollar four spark plug wires on the two coils because two of
the wires broke at the spark plug, necessitating needle-nose pliars to pull
the stuck-on metal caps off the plugs.
For 30 seconds, we removed the 15 amp EFI fuse in the engine compartment
next to the battery, which reset the OBD II memory.
Time will tell but the yellow emissions control check engine light stayed
off during a test drive and the prior stumbling disappeared. I'm amazed
that plugs would last 100,000 miles (they were the normal j-gap type, not
This is written so that you may comment to help us and others. The main
problems we ran into were the Belden ignition wires didn't stay on the
coils as the clip was about a tenth of a millimeter too small so it took
about fifteen minutes to get the coil side of the wires on correctly.
The only other problem was that two of the ignition wires broke at the top
of the plug, necessitating needle-nose pliars to extricate them. As
recommended, we used no lube on the spark plug threads so we can rest
assured the 14 foot pounds is accurate.