Mazda 6 Forums banner
1 - 20 of 21 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter · #1 ·
Hello,

I have a 16 Mazda 6, MT, with 101500miles. I changed the spark plugs 25k miles ago and just recently changed the coils when this issue started. I'm still having an issue with this backpressure situation upon hard acceleration at 3k+ rpm. Searches on this forum provided no similar situations.

I have a Tanabe axle back exhaust. Google searches lead me to believe it's a resonator/cat issue. Could it be a dirty MAF? Keep in mind, this misfire or backpressure can only be heard or felt behind me in exhaust and not the engine. Engine idles smooth and no CELs. It has been like this for a few months now. I'm thinking my next guess is to buy a resonator and have a exhaust shop install it. Looking forward to hear what you guys suggest!
 

·
Registered
2016 6
Joined
·
455 Posts
Hello,

I have a 16 Mazda 6, MT, with 101500miles. I changed the spark plugs 25k miles ago and just recently changed the coils when this issue started. I'm still having an issue with this backpressure situation upon hard acceleration at 3k+ rpm. Searches on this forum provided no similar situations.

I have a Tanabe axle back exhaust. Google searches lead me to believe it's a resonator/cat issue. Could it be a dirty MAF? Keep in mind, this misfire or backpressure can only be heard or felt behind me in exhaust and not the engine. Engine idles smooth and no CELs. It has been like this for a few months now. I'm thinking my next guess is to buy a resonator and have a exhaust shop install it. Looking forward to hear what you guys suggest!
Did you remove the stock cat and stock resonator?
 

·
Registered
Joined
·
1,487 Posts
Hello,

I have a 16 Mazda 6, MT, with 101500miles. I changed the spark plugs 25k miles ago and just recently changed the coils when this issue started. I'm still having an issue with this backpressure situation upon hard acceleration at 3k+ rpm. Searches on this forum provided no similar situations.

I have a Tanabe axle back exhaust. Google searches lead me to believe it's a resonator/cat issue. Could it be a dirty MAF? Keep in mind, this misfire or backpressure can only be heard or felt behind me in exhaust and not the engine. Engine idles smooth and no CELs. It has been like this for a few months now. I'm thinking my next guess is to buy a resonator and have a exhaust shop install it. Looking forward to hear what you guys suggest!
Just thinking about this... (rhetorically) what would cause a resonator to plug off, though?
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #5 ·
Just thinking about this... (rhetorically) what would cause a resonator to plug off, though?

That's why I'm wondering if it is something simpler like a dirty MAF. If the resonator is clogged, I don't know what would cause that. It's even weirder to me that the car doesn't show any CELs.

Should I try new plugs? Looking for suggestions
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #6 ·
Just thinking about this... (rhetorically) what would cause a resonator to plug off, though?
Should I try changing plugs again? Clean the MAF? No CELs so looking for suggestions. I don't know what would necessarily make a resonator get clogged if it really is the resonator that's causing the backpressure/hesitation.
 

·
Rally Racer
2004 Mazda 6s Wagon ATX
Joined
·
3,585 Posts
Hello,

I have a 16 Mazda 6, MT, with 101500miles. I changed the spark plugs 25k miles ago and just recently changed the coils when this issue started. I'm still having an issue with this backpressure situation upon hard acceleration at 3k+ rpm. Searches on this forum provided no similar situations.

I have a Tanabe axle back exhaust. Google searches lead me to believe it's a resonator/cat issue. Could it be a dirty MAF? Keep in mind, this misfire or backpressure can only be heard or felt behind me in exhaust and not the engine. Engine idles smooth and no CELs. It has been like this for a few months now. I'm thinking my next guess is to buy a resonator and have a exhaust shop install it. Looking forward to hear what you guys suggest!
Hello, if you have had a mis-fire for months now there is a good change that the catalytic converter disintegrated and has plugged up the works downstream. This happened to my Mk1
 

·
Registered
Joined
·
4,202 Posts
Hello, if you have had a mis-fire for months now there is a good change that the catalytic converter disintegrated and has plugged up the works downstream. This happened to my Mk1
Id think that too, but its a 3rd Gen.

OP, How do you know its "back pressure" or a misfire? Can you elaborate more?
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #9 ·
Did that situation trigger a CEL? I decided to make an appointment to bring it to a Mazda dealer tomorrow but, only for a diagnosis. I don't plan to get the fix there.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #10 ·
When I accelerate onto an on ramp, the car noticeably hesitates, sometimes up to 4 times. I can hear the exhaust make these puff/gasping noises like it's clogged if that makes sense. It feels like it jerks the car and I can hear the puff/gasping noise behind me, directly underneath the car. It really affects the linear power delivery.

I'll downshift and hit the accelerator and it does what I described above. It doesn't always act in the same manner. Sometimes it's less, sometimes it doesn't do it at all. It's just baffling it hasn't had a CEL yet.

This has recently started happening after a minor front end collision. My car was parked on the side of the street and a DUI driver side swiped the front end on the driver's side, only requiring a front strut, wheel bearing, and new wheel besides the dent/paint repair.
 

·
Registered
Joined
·
21 Posts
Discussion Starter · #12 ·
So the dealer got back to me and says it's a misfire in cylinders 1 and 4. They suggest injectors, plugs, and coils. How would that not be triggered by a CEL?

Could it just be carbon build up?? My previous car had a similar issue without a CEL and that's what it was.
 

·
Registered
2017 Mazda6 GT
Joined
·
17 Posts
So the dealer ... says it's a misfire in cylinders 1 and 4. ... How would that not be triggered by a CEL?

A misfire must happen a specific number of times in a specific period for a CEL to be tripped (and even more to make it flash). You could be having misfires all the time but under the limit and it wouldn't trip. In an OBDII reader there should be misfire counts for each cylinder (but not always) in the live data. It would be able to see the misfire counts going up and only when they go up fast enough would it trip a P030# code.

P0300 code is usually something like a vacuum leak, plugged exhaust (basically something that could affect every cylinder. Where a P030[1-4] (or slowly rising misfire count on a cylinder [1-4]1) would likely be a plug, coil, injector, compression, etc. on cylinder [1-4] (basically something specific to cylinder [1-4]).
 

·
Registered
Joined
·
34 Posts
Should I try changing plugs again? Clean the MAF? No CELs so looking for suggestions. I don't know what would necessarily make a resonator get clogged if it really is the resonator that's causing the backpressure/hesitation.
I had a similar issue at 1800 revs. Found that 2 of the new spark plugs were faulty. Changed spark plugs... all good again
 

·
Registered
Joined
·
4,202 Posts
AH, do they use different tech on the converters? I was under the impression they used a manifold converter and a downstream converter as well. I'll be the first to admit I don't know the 3rd gen cars like I do the 1st gen.
🤷‍♂️
Way newer tech, but i meant i didnt think the car was old enough to succumb to this. I mean, YMMV and i could always be wrong, but thats what i meant by it.
 

·
Registered
Joined
·
34 Posts
What came of this? I am having a similar issue (code p0301) even after new coil and new spark plug.
In my case, the $%#& mechanic didn't bother to check the spark plugs..... or worse. According to the new mechanic, "They look like they have been in a while" so the question is, did they actually replace them in the first? Or just clean them? Two of the spark plugs were split top to bottom which I believe can only happen when incorrectly fitted - leaning to one side while screwing in.
 

·
Registered
Joined
·
9 Posts
Oh, damn! That’s terrible. Glad you figured it out. Maybe I have faulty spark plugs?! They’re new and put in well b/c my mechanic is me and my dad 😉. I’m thinking could be a clogged injector possibly. Sigh...

thanks for the update!
 
1 - 20 of 21 Posts
Top