2002 Protege5 Bad Misfire and Fireworks Smell

[p5deepblue]

Any ideas? Just replaced plugs and wires because the CEL code was P0300 or misfiring. Also threw a P0421 at some point. The actual violent misfiring didn't start until new plugs and wires were in. I'm guessing that I plugged up the cat converter driving with a small misfire for too long.

 

[kms1990]

maybe, sounds like you may have a failing coil theyre $40 at autozone in my locality.you need 2. that smell is most likely the inside of the coil where it produces the high voltage, maybe has a short or crossed wire in it.

 

[rj1784]

If the car ran for long while misfiring more than likely the catalytic converter is destroyed. It doesn't take much raw gasoline to ruin the convertor. It happen to me in my miata when I was on my way to work years ago. I drove the car less than 1/4 of a mile with it misfiring.

 

[kms1990]

depends on misfire though, if really bad cat can be toast if minor start elsewhere. fireworks smell wouldnt be indicitive of a cat to me thats a sulfur or bad egg smell usually

 

[p5deepblue]

It was a minor reverse shudder and mild occasional misfiring that threw a CEL with a P0300 code as the reason. I was driving it with the CEL light but it felt ok. Then one night this week it started flashing while I drove, so I replaced the plugs, wires and the boots under the coils and then shortly after the violent misfiring started.

 

[kms1990]

yeah sounds like 1 of the 2 coils failed. seems to hit these cars weird, when you do the tune up it shows up, its odd. i would go ahead and replace both coils to start but before you do, check your coil boots that u replaced make sure they are put back correctly, thats a common issue as well.

 

[p5deepblue]

Are AutoZone coil packs any good or should I order better ones online or something?

 

[p5deepblue]

Plugs are NGK btw, wires are duralast.

 

[Big Ds mp5]

Did you disconnect your battery to reset the ecu?

 

[kms1990]

duralast coils arent bad, i have used them on many cars without issue. lifetime warranty anyway so if they do act up take it off get another throw it on. what type of ngk plug is it copper? platinum, double platinum or iridium and how long have they been in the car? how old are the wires even if not old if you bought them replace them under warranty

 

[p5deepblue]

All spark related parts are new:

-Plugs (Just standard NGK's, the cheap ones. At the office so not sure of any other details.)
-Wires (Duralast)
-Boots (Duralast)
-Coil Packs (One Duralast and one Intermotor/BWD)

I have two different coil packs because Advance had just one and AutoZone had just one. After installing the new coil packs there is no violent misfire and the CEL light never came on with the next start. I did not have to clear codes or disconnect the battery. It still feels a bit rough when idling. More like a fast vibration but not a misfire. Anything else I should check on? Heading to Kentucky tomorrow and it is a few hours away, so better safe than sorry. Thank You

 

[kms1990]

check your hoses fore rips or tears, maybe go ahead and do pcv valve its $3 at autozone and a 2 minute job wont hurt, check/clean/replace the egr valve

 

[kms1990]

any news on the problem?

 

[hornsfan10609]

If the battery has been disconnected the ECU is still relearning and the idle may not be as smooth at first but it will be after you drive it a bit.