Sailingsenses
Member
- :
- Mazda, Protege5, Stock, 2002
Hi all,
Stock P5, no mods.
More misfire problems, but why so freakin' soon?
August 2015, at 301,375 Miles, CEL came on, two codes: P0302 & P0172
Did all of the following:
- Ignition Coil Packs (2)
- Wires (2)
- V-Power Spark Plugs (4)
- PCV + Grommet (was a wreck)
- Professional Fuel lines chemical cleaning (nothing was clogged but I went ahead)
- Sea Foam in tank
- Air filter
- MAF cleaning (only)
- Intake hose (was cracked)
Both codes went away after all that ^^, no issues until late March 2016 (today CEL came on, 4/02/2016).
Fast forward to late March 2016 (309K+ Miles), and the car was acting off coming out of a stop, as if there wasn't enough power, then it drives perfectly fine. I thought the soggy weather was to blame, but it happened when it was warmer and bone dry out, too. Finally, the CEL came on today.
April 2016, at 309,700 Miles, CEL came on, one code: P0303
- For now, all I've done is erase the code and swap out the two coils to test, and I will need to drive it until cylinder misfires or does not. Likely 50 miles or so.
Note from manual and "PCB" here on the forum:
<> Swapping coils should give a code (P0301) or code (P0304) if the misfire follows the coil.
<> Cylinders 1&4 fire simultaneously and cylinders 2&3 fire simultaneously. (Wasted spark ignition.)
WHY would this be happening again so soon? I replaced everything that usually causes these misfires back in August of last year, just over 8K miles ago.
I planned on replacing the EGR but have not bothered, as it's hard to reach and I suspect the bolts are impossible to remove. Also, I've never had any EGR related codes, so is it safe to assume it's fine? It would produce its own code, right?
Any idea why misfires would come up again so soon? I hear a lot about faulty coils, but how much of that is true? I also see posts where replacing them or swapping them around does nothing to resolve this. The service manual points to some things I wouldn't have a clue how to investigate.
The one thing that has been going for YEARS is this annoying sputtering sound ("pinging"?) and it does seem more obvious to me now. This is only audible off a stop, but the car runs like a dream otherwise. Also, the Neg battery (battery is under two years old, highest quality) terminal is all foamed up/caked. I don't think any of this is related, but thought to add that in. I do wonder about the fuel pump and EGR, but without other codes pointing in that direction, should I bother replacing them?
Please help! Thanks so much.
Stock P5, no mods.
More misfire problems, but why so freakin' soon?
August 2015, at 301,375 Miles, CEL came on, two codes: P0302 & P0172
Did all of the following:
- Ignition Coil Packs (2)
- Wires (2)
- V-Power Spark Plugs (4)
- PCV + Grommet (was a wreck)
- Professional Fuel lines chemical cleaning (nothing was clogged but I went ahead)
- Sea Foam in tank
- Air filter
- MAF cleaning (only)
- Intake hose (was cracked)
Both codes went away after all that ^^, no issues until late March 2016 (today CEL came on, 4/02/2016).
Fast forward to late March 2016 (309K+ Miles), and the car was acting off coming out of a stop, as if there wasn't enough power, then it drives perfectly fine. I thought the soggy weather was to blame, but it happened when it was warmer and bone dry out, too. Finally, the CEL came on today.
April 2016, at 309,700 Miles, CEL came on, one code: P0303
- For now, all I've done is erase the code and swap out the two coils to test, and I will need to drive it until cylinder misfires or does not. Likely 50 miles or so.
Note from manual and "PCB" here on the forum:
<> Swapping coils should give a code (P0301) or code (P0304) if the misfire follows the coil.
<> Cylinders 1&4 fire simultaneously and cylinders 2&3 fire simultaneously. (Wasted spark ignition.)
WHY would this be happening again so soon? I replaced everything that usually causes these misfires back in August of last year, just over 8K miles ago.
I planned on replacing the EGR but have not bothered, as it's hard to reach and I suspect the bolts are impossible to remove. Also, I've never had any EGR related codes, so is it safe to assume it's fine? It would produce its own code, right?
Any idea why misfires would come up again so soon? I hear a lot about faulty coils, but how much of that is true? I also see posts where replacing them or swapping them around does nothing to resolve this. The service manual points to some things I wouldn't have a clue how to investigate.
The one thing that has been going for YEARS is this annoying sputtering sound ("pinging"?) and it does seem more obvious to me now. This is only audible off a stop, but the car runs like a dream otherwise. Also, the Neg battery (battery is under two years old, highest quality) terminal is all foamed up/caked. I don't think any of this is related, but thought to add that in. I do wonder about the fuel pump and EGR, but without other codes pointing in that direction, should I bother replacing them?
Please help! Thanks so much.
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