I have a dam 99 with 51k miles and already got a P1320 code. So I just replaced all the coilpacks with brand new ones and my car still runs like sh*t. Engine light, tcs are on and I have a bad misfire going on. Any suggestions as far as what else could be causing the misfires when I just replaced all the packs with new ones?

 

also replaced PCV and plugs (NGK PLat's) 2 weeks ago.

 

if it was the coil packs that were bad, it would not trigger any codes..

 

not true. they will trigger the cel if they are really bad.

my suggest to you would be to get your injectors checked out. ive got 2 extra ones if your in need.

 

Check the crankshaft and camshaft sensors. Dont rely on just the lights. There's a way to check them with an ohmmeter. Check any shop manual.

If they are ok, my money is on a bad injector. I dont have a lot of time right now so this will be brief but here's what you need to do.

Take off the spark plug cover thing. Loosen and remove all of those little bolts holding the coils.

With the motor on, remove and reinstall one coil. See if the engine runs worse or if it runs the same. If it runs worse, this cylinder is firing properly. Reinstall that coil and repeat this with another one. Do this and hopefully you will find one cylinder where you remove the coil and it runs the same.

If and when you do, remove this coil pack and put the plug end (part that goes on the spark plug) close to a point that is grounded. Listen for a "tick tick tick" noise.

If you hear the tick noise it means your ignition is firing.

You need ignition and fuel for a cylinder to fire. If you have ignition but no fuel, it will miss.

This is the fuel injector you need to replace.

Do not do this if there is fuel around. Do not do this on wet ground or if your hands are wet.

If nothing works, you might have a bad ECU, your timing chain might have slipped, or your motor has a bad cylinder.

Let us know what you find

 

wow with motor on and removing the igntion coils. damn thats dangerious. be prepared to be shocked by 8,000-20,000 volts if your not properly insulated. just ohm them out.

to check injectors, with a long flat head screw driver. and putting it right by the injector as it is firing. and see how long each pulse width is. another way would be to use a portable temperature sensor. point it at each cylinder and compare the temperatures. the lower temperatures usually indicate that the cylinder is misfiring.

 

reset the ecu and see if you are still getting getting the ignition circuit code.
check the connection plug on the coil and look for any corrosion/melting.

i dont mean to undermine you but what was the car running well before the NGK's? are they gapped correctly , correct part number...when you pulled the old plugs did you see signs of a misfire on a particular cylinder?

55k and a 99 seems early for a fuel injector but who knows