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2004 5-speed, w/ LSD & Sport package 馃槑
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Discussion Starter #21
Okay, oddly enough I'm getting the dreaded p0420 code, i think the misfire is eating at my cats. Somehow though, I feel like the car is more powerful, as if it freed up +5 hp with the new coil packs...
 

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2004 5-speed, w/ LSD & Sport package 馃槑
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Discussion Starter #22
Okay, oddly enough I'm getting the dreaded p0420 code, i think the misfire is eating at my cats. Somehow though, I feel like the car is more powerful, as if it freed up +5 hp with the new coil packs...
Update: i took my IS to Mexico to test out my max speed (142 according to multiple speed tracking apps and my laser jammer) and after returning home to normal highway speeds, i got 7 CEL codes. p0300, p0303, p0304, p0301, p0306, and p0420. I have already changed my coilpacks to OE NGK coilpacks that legit have the toyota part # and have TOYOTA stamped on them. I have noticed that my car's releasing more loud bangs and whooshes (baby flames) and that's probably causing my p0420. I know that Solar has suggested checking my cam and crank sensors, but I don't think it's either of those because when I havd my cheap chinese coilpacks it NEVER EVER misfired until they died...
 

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2004 5-speed, w/ LSD & Sport package 馃槑
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Discussion Starter #24
Clogged cats can cause misfires.
Update: I went to Rockauto and bought some NGK coilpacks, and it semi-fixed the issue. I had my diagnostics guy help me confirm it was a coilpack issue and not a sensor issue, as well as cleaning the TB, Int. Y-pipe, and intake plenum/runners. My CEL's are indicating it's coilpack number 2 (for cylinders 3 &4). I also verified my igniter was not bad, by swapping another DH61 igniter from an 01 is onto mine, but it did not fix the issue. Is it possible rockauto sent me a bad coilpack 2 times in a row?
 

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Okay, so here's my tale of sorrow...

when i first got my 5 speed IS, i thought it was running fine. Yet, somehow there was popping on idle. I didn't think much of it. I then proceeded to buy cheap chinese coilpacks, and they eliminated any and all popping, however, they quit after only about 4 months of use. I then manned up and overhauled most of my ignition system: New OEM denso coilpacks, NGK plug wires, and new replacement connectors, yet i still have a misfire in 1st gear when i go to 50% throttle it after it's idling (while moving in 1st gear, i don't know if i explained myself well there). I made sure my pins are in the right spot, and that i didn't swap any plug wire locations over to where they don't go (coilpack #3's plug wire goes to cyl 6, coilpack #1's wire goes to cyl #5, and coilpack #2's wire goes to cylinder 3). Has anybody had a similar issue? My old coil packs are slightly worse than the newer ones, with a more noticable misfire at idle. I'm running out of options as to what's wrong... Since I have an '04, my igniter is a DH61, so should i try replacing it? if so, would a used one be a safe bet? I'm not very knowledgeable when it comes to diagnostics with misfires besides "unplug that injector and see if it still misfires" kind of diagnostics. Also, This is my first post here, so please go easy on me if i did something wrong.
If there is any moisture in between the valve covers and in the three plug and coil bays this will cause arcing and misfires.
 

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2004 5-speed, w/ LSD & Sport package 馃槑
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Discussion Starter #28
If there is any moisture in between the valve covers and in the three plug and coil bays this will cause arcing and misfires.
I went ahead and ordered a new coilpack from allNGKparts.com and it's going to be fixed once and for all
 

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I went ahead and ordered a new coilpack from allNGKparts.com and it's going to be fixed once and for all
allNGKparts.com you say? I couldn't find that site, maybe you meant somewhere else?

Either way, just be cautioned about coil packs in general, if you're not familiar with their construction, they need to be manufactured in a very special way, so hopefully whatever you ordered wasn't a super cheap chinese knockoff. They tend to have very short lifespans due to their cheap construction, typically enough to get you by for a maybe a year. Now, if the site you mentioned is anything to go by, I would guess it's an NGK coilpack, which is a pretty good known brand, but I don't know how well their construction is for a coil pack for our cars.

...I have already changed my coilpacks to OE NGK coilpacks that legit have the toyota part # and have TOYOTA stamped on them. ...
As far as I know, the OE replacement is Denso, but hopefully you have good performance and reliability with the NGK's
 

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I went ahead and ordered a new coilpack from allNGKparts.com and it's going to be fixed once and for all
NGK is the way to go. Expensive but worth it. They last long. Just make sure those bays are free of moisture, oil and coolant.
 

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2004 5-speed, w/ LSD & Sport package 馃槑
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Discussion Starter #31
allNGKparts.com you say? I couldn't find that site, maybe you meant somewhere else?

Either way, just be cautioned about coil packs in general, if you're not familiar with their construction, they need to be manufactured in a very special way, so hopefully whatever you ordered wasn't a super cheap chinese knockoff. They tend to have very short lifespans due to their cheap construction, typically enough to get you by for a maybe a year. Now, if the site you mentioned is anything to go by, I would guess it's an NGK coilpack, which is a pretty good known brand, but I don't know how well their construction is for a coil pack for our cars.



As far as I know, the OE replacement is Denso, but hopefully you have good performance and reliability with the NGK's
sorry, i meant sparkplugs.com, which is a legit NGK authorized seller, unlike Rockauto
 

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2004 5-speed, w/ LSD & Sport package 馃槑
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Discussion Starter #33
it's cool, did you manage to get the car running good?
Somewhat... The car runs significantly better, but it still misfires under high load. Same proble, less frequency. It's not my igniter, plugs, but I suspect it might be my spark plug wire for those cylinders, because when I swap the coil it stays at those cylinders... Damned Amazon NGK plug wires
 
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