Rough Idle L4

[OddJack]

I had very poor idle and car running shakey. Engline light came on. I changed the spark plugs NGK IR and it was good for couple of days but then again the shaky idle comes back. It feels like one of the cylinders not firing. No maintenance done last 30000 miles, car has 99k miles.

What else can I change?, What would be the equivalent of spark plug wires?

[Redline_Me]

might be getting flooded. make sure the plugs aren't over tightened and torqued to the right specs. might be the coil too.

check which one of the plugs is black and that's the one that's getting flooded.

[OddJack]

How often is the coil changed? every tune up? How hard is it to change it?

2002 L4 Camry

[Redline_Me]

not often at all. But if you're having problems than why not, you got some miles on that thing so do a full tune up.

[fatngs]

i work in auto parts and i kno that coils arent cheap on that engine so i would get the check engine light diagnosed first.... if its a cylinder misfire it will tell you which one

[OddJack]

Yes, very expensive. Over $250 for a set.

I just ordered a obd II reader.

[jbbnet]

you should be able to determine which coil it is by the code, but which coil is for which cylinder? Does the v6 camry 2grfe use one coil for a pair of cylinders?

[joshuaboston]

auto zone will read the code for free.

I would also check to make sure all your coils are in properly. Perhaps buy some dielectic grease and add a bit to each coil... where it contacts with the spark plugs.

[joshuaboston]

goog luck

[TOYO-ED]

Perhaps the IAC valve is dirty?

Check this link to see further details:
How to: Cleaning Throttle Body -4 Cylinder Engines- With Pictures