Keep having Misfire issue.....

zizaspeed

Member
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2004 RX8
yeah on the freeway my wife always complains while i'm accelerating she can sometimes smell rotten eggs....thinking of just putting header on defouler.

I luckily passed emissions 2 weeks ago....As i pulled out of the center my CEL came on LOL
 

mp5build2013

Member
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Mazda, Protege5 02
Thanks for the info. What I've noticed is when i have almost no gas meaning the light will be on soon, my cel goes away . And stays off until I pump gas and start driving. Im wondering if this is related to my fuel Pressure regulator.

I'm also considering getting a header cause ive been hearing a rattle coming from what appears to be the cat and a strong smell on freeway

that sounds like a clogged up cat. you can just remove the front pipe at the botton of the cat and inspect the hone with a light if its intat youre good. mine was churned up and melted into a ball. and because of that i was running hot as well. and belive it or not, the gas you use has a lot to do with your power and fuel consumption. a lot of ppl say to stick to reg unleaded but ever since i started using Vpower gas from shell my car runs better, and the smell of raw gas is gone too. check you fuel pressure regulator too though, disconnect the vacuum and see what happens.
 

mp5build2013

Member
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Mazda, Protege5 02
oh and i forgot!, seafoam it! it may just be dirty and your induction system may be clogged up with grime. a lot of guys on here will agree, seafoam works.
 

zizaspeed

Member
:
2004 RX8
Remove which vacuum hose? The one on regulator? Yeah I have sea foamed in the past, bout a year ago, guess I could do it again
 

balilewis

Member
Sorry to hi-jack the thread but I'm experiencing the same problem and I'm frustrated beyond means because this is my daily driver and I can't afford to bring it to the shop. Same code: P0302.
Started last Thursday, noticed the car is idling rough and the CEL will blink intermittently when driving.

I bought a coil pack and a set of spark plugs (Bosch <-- dumb mistake) and swap one of my coil pack (the one closest to the passenger seat) and all four spark plugs. Car runs better, no CEL and no idling rough. Smooth rev.
This lasted for a couple days. CEL came on when car is idling on Sunday, same code but the idling is not as rough as last Thursday. Still smooth rev.

I then bought NGK spark plugs to replace the Bosch ones and I bought new wires and a new coil pack so that I'll have brand new wires, coil packs, and plug wires. Changed everything last night, turned on the car this morning and the idling is back to rough, CEL came on and it blinked intermittently again on the way to work. Engine rev is not smooth at all.

Any ideas on what I can do? I plan to work on it during lunch. There's also an Oreilly's auto store a mile away that I can drive to.
 

mp5build2013

Member
:
Mazda, Protege5 02
Sorry to hi-jack the thread but I'm experiencing the same problem and I'm frustrated beyond means because this is my daily driver and I can't afford to bring it to the shop. Same code: P0302.
Started last Thursday, noticed the car is idling rough and the CEL will blink intermittently when driving.

I bought a coil pack and a set of spark plugs (Bosch <-- dumb mistake) and swap one of my coil pack (the one closest to the passenger seat) and all four spark plugs. Car runs better, no CEL and no idling rough. Smooth rev.
This lasted for a couple days. CEL came on when car is idling on Sunday, same code but the idling is not as rough as last Thursday. Still smooth rev.

I then bought NGK spark plugs to replace the Bosch ones and I bought new wires and a new coil pack so that I'll have brand new wires, coil packs, and plug wires. Changed everything last night, turned on the car this morning and the idling is back to rough, CEL came on and it blinked intermittently again on the way to work. Engine rev is not smooth at all.

Any ideas on what I can do? I plan to work on it during lunch. There's also an Oreilly's auto store a mile away that I can drive to.

this sounds more like cracked intake hose, or egr.

check for cracks in the induction system by spraying carb cleaner slowly by all the hoses with the engine running, if the engine revs up on its own you have a leak/crack.

check you cat. conv.
remove the upper o2 sensor, run the car... it will be loooud, but if your cat IS clogged, this will relieve it. IF it is not, it will just be louder and the rough idle will continue

tap your MAF sensor lightly with the engine running, if you hear a change in the idle you are good. if you tap and tap and nothing, replace MAF.

thats about all i can think of that can be checked at lunch..

oh, and if your intake makes a loud whistle sound under 4000 rpms check your rubber hose connectors on your intake you probably have leak. but the carb cleaner trick i mentioned above should spot that.
 

zizaspeed

Member
:
2004 RX8
Yeah I would check for a cracked intake hose, in the accordian looking section. NExt step would be cleaning/replacing EGR .

So mp5build, you mentioned removing vacuum hose off regulator, which I did today just for about a minute and nothing seemed to change about the car while it was running? ..
 

mp5build2013

Member
:
Mazda, Protege5 02
Yeah I would check for a cracked intake hose, in the accordian looking section. NExt step would be cleaning/replacing EGR .

So mp5build, you mentioned removing vacuum hose off regulator, which I did today just for about a minute and nothing seemed to change about the car while it was running? ..

im sorry i didnt just tell you what to look for with the fuel pressure reg.
if you disconnected it and nothing happened your fuel press reguator is good.
when the regulator goes bad, the vacuum line sucks up fuel flooding the engine. if you were to disconnect the vacuum and the engine sounded like it began to breathe better, that regulator is shot.
 

zizaspeed

Member
:
2004 RX8
When I'm testing it, when I pull the hose off should give it a little throttle or no?

And Could you post a pic of how you have your MAF sitting ? If you get a chance, I want to compare it with mine, thanks for all your help
 

zizaspeed

Member
:
2004 RX8
so today I installed an ebay obx style header, EGR fitment doesn't line up so I'm gonna need to find a way to clog it on the header or block it? Any suggestions? If I do this will my egr valve be always open or closed?

Since my header install I'm getting some nasty squeeking from what seems to be a little further down the exhaust pipe?
 

zizaspeed

Member
:
2004 RX8
Well fixed my squeeking issue, turned out to be the heat shield I had bent to make room for my short shifter was now rubbing the exhaust. As for the EGR fitment on the header, seems it's a typical problem with the ebay header and I'll just have to block it off. My concern is how is the EGR valve going to like that?
 

zizaspeed

Member
:
2004 RX8
Well got the breather filter on egr cut pipe, works fine. Started off buy using some steel puddy to block off egr fitment, can see in picture, that failed and made the car smell like doodoo. Went to home depot and into plumbing section and found a large enough screw to cover the fitment. Still getting an annoying vibration which I've isolate to also be from this ebay header, where it meets the exhaust, is now rubbing the oil pan.....Tried putting a silicon coupler inbetween, that worked temporarily but must have came out cause vibration is back lol

20130910_154949.jpeg 20130910_154958.jpeg
 

mp5build2013

Member
:
Mazda, Protege5 02
ill post a pic later today of my maf, but it is nothing special it is mounted to the battery mount. i place the pipes to where they DO NOT tap on anything. i tried using a mount on my engine but the vibrations were wayy too hectic to i just put it back on the batt mount. i also have an ebay header and i also tried all tricks to get that egr pipe to fit but nope. i ended up clogging it with high heat putty, works great if you dont mind not having the valve... i have a breather and pipe cutter in the backseat lol... havent really wanted to do it i guess... how much of a difference does it make??

btw, i have a HUGE rattle coming from the end of the header..where it meets the cat-back pipe. this weekend when i get my grinder to take off my end-links im going to grind that down too to keep it from hittin the housing. about the misfire...oriellys in my area just started stockin JAPANEESE coil packs i traded my chineese ones in and it made a huuuuge difference. my injectors were really dirty for some reason too, it took two fill ups with lucas to clean them out, i actually felt them sputter their way back to smooth injecting.
 

zizaspeed

Member
:
2004 RX8
Yeah the puddy i used didn't work lol glad its working for ya though. Doesn't really make a difference at all to be honest but it looks nicer than having the pipe just sit there lol.

Yeah I have changed the coils with new ones twice now, ones from autozone still had the issue so then I ordered some online and put those in. So I don't think the cause is from the coil packs, I've changed spark plugs to the long reach ones as well and did notice a smoother throttle response. I changed fuel injectors awhile back for some used ones, still had the problem. More recently I took my fuel housing apart and replaced the sock and pump housing. I'm thinking about replacing the fuel regulator now....
 

mp5build2013

Member
:
Mazda, Protege5 02
have you already switches gas? try running your gas to almost empty and put some 87 chevron or shell gasoline. Or the lowest octance avail. at either of those 2. take it for a cruise.. if you feel a difference, either for better or worse, you probably have a bad gas/spark plug combo. when i was running ngk platniums v-power ran great, now that i went back to copper there is not enough spark to ignite all that octane and it begins to run a bit "drowned". i have found ngk iridiums to work great with regular shell gas. OH! and very imprtant, SPARK PLUG GAPPING. Iridium plugs are VERY sensitive! when i bought my first pair they were gapped at .30 i figured i had to gap them up to .44.... well i bent the tips attemting to gap them, so i had to toss them. i couldnt find a good gapper so i bought new ones and threw them in as they came,.30 they run well but i think i will find a different brand of iridiums that come pre-gapped at .44 just to have the peace of mind of my gapping and not have to mess with it next time i change them out... (i get new ones every 3 months)
 

mp5build2013

Member
:
Mazda, Protege5 02
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here is an old pic of my bay, i have a new MAF now, but it is still in the original place.
see that wire wrapped around my radiator hose? thats my o2 sensor, just hanging out. Some people say they can be an issue, its back in the pipe again, but it really didnt matter car acts the same.
 
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mp5build2013

Member
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Mazda, Protege5 02
so i said what the hell and went and took pictures of it... here are some fresh pics...
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cant really tell in the picture, but they are not even close to touching


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zizaspeed

Member
:
2004 RX8
Yeah my MAF is mounted the exact same way. Honestly I'm done trying to figure out the misfire lol pretty much done with this car. Just gonna maintain is with regular maintenance and try and get an EVO or something within a year or 2. I passed emissions so that gives me another 2 years lol

I will try and regularily pump at chevron/shell though, even though arco or safeway gas is so much cheaper........we'll see lol