[2004-6S-RochesterNY]

I'm posting this in hopes it helps someone, or that someone might reply to tell me if I'm facing additional issues (or if I should take any precautionary measures to prevent additional problems).

Here's the story -- and what I've done so far:

All good since 2004 when I bought the car new. Mazda 6s hatch - LOVE this car for many reasons. Best one = I can sleep in the back during long drives or if I'm stuck away from home. Totally flat and comfortable. It's a freakin' SUV in wolf's clothing.

So, one day I get a CEL (80k miles now). Tighten gas cap, check oil... Uh-oh. Oil just touching bottom of the stick. Add oil. Monitor daily. Oil goes down a quart per 100 miles. Damn. Check internet forums (thanks guys!)... and freak out that I'm gonna toast the motor (or have already).

Try to find a new car that I like... can't find anything better than my Mazda (looked at new Audi 3, Mazdaspeed3, etc.).

Note to self: Relax man, you need to chill out. Buya new car because of some CEL? Douche-bag... just fix it pussy-boy!!!

My mech replaces PCV and does a general full-car check. Needs CV boot, needs ball joint, needs some other crap. No biggie. Do it all. Mech clears the CEL. He says NOT to worry about the pre-cat or cat (??), but that the consumption may be either PCV or valve job ($$$!!!).

I drive car -- second day I get CEL again. Back to garage. Same codes (P0171 = lean fuel condition and P0172 = rich fuel). WTF? More research needed here, go back online. Could be mass air flow sensor, could be vacuum or throttle body leak, could be air delivery something.

BTW - I'm the guy who NEVER messes around my car. Just put in gas, do whatever the mech dudes recommend. I changed the cabin air filter once, whoop-de-freakin-do for me.

So I check under the hood. Scratch my chin. Find rotted & cracked air intake hose (the accordian thingy), and a pretty filthy air filter. Order both online for ~$100 or so. I can handle this part !!

Will install this weekend and report back. If those don't help, my next steps are MAF sensor and\or repl vacuum hoses \ throttle body gasket right? I'll do the MAFs, but it's back to the mech for anything else.

Car drives fine -- and has the entire time. The ONLY thing I've noticed is minor surging when at a stop light (car is "pushing" against the brakes, wants to go-go-go) or when in gear and coasting at idle (it's like I'm hitting the gas very lightly when I'm not). I hear this can be related to my P0171 \ P0172 codes.

Hope this helps somebody who has similar symptoms.

What am I missing -- any advice?

 

[e4w]

change your spark plugs(double platinum$4 ea from Mazda) and coils, for the surging. be careful with that lean/rich issue too. those precats are sensitive and will destroy your motor...you might want to think about O2 sensors too.

[email protected],000+check the coils(6) for cracks on top
[email protected] or near 100,000

 

[cmorty72]

change your spark plugs(double platinum$4 ea from Mazda) and coils, for the surging. be careful with that lean/rich issue too. those precats are sensitive and will destroy your motor...you might want to think about O2 sensors too.

[email protected],000+check the coils(6) for cracks on top
[email protected] or near 100,000

This^
Also, try using MAF cleaner and clean your MAF sensor. I'd bet that along with the cracks developing on your intake arm, you've got your share of dirt and dust in there that can foul any MAF sensor.
Here's a how to:
Mazda6Tech - How-To Clean Your Maf Sensor

 

[2004-6S-RochesterNY]

Quick update --

I cleared the CEL by removing the black battery cable, pumped my brakes, waited 10 minutes, reconnected. All clear.

I then duct taped the air intake accordian thingy (temporary fix, of course) and all symptoms have now gone away. Maybe some surging still but so minor that it's not really even annoying.

I'll ride it like this, install the replacement parts as noted above when they arrive, and report back. Should I need to go furhter with more fixes, I'll let you all know.

BTW - don't you HATE IT when people don't close out their threads with the end of the story? That's my pet peeve. L8tr.

 

[2004-6S-RochesterNY]

It's now been 4 days and still no symptoms at all. Surging has also stopped.

Damn, but if this ain't another case of duct tape to the rescue !!!!

Will update this thread only if the replacement parts don't help... or if I need to do anything additional to resolve the issues.

 

[2004-6S-RochesterNY]

Replacement air intake installed - still no problems.

I'm closing this thread and really hope it helps somebody out there.

 

[cmorty72]

So from the sounds of things a dirty MAF was an issue.
Don't know if you're interested, but there's currently a gauging interest thread going on a another forum for a far better replacement for the stock accordion arm on the intake:stock intake accordian tubes - 6Crew.com Forum

 

[2004-6S-RochesterNY]

Nope -- MAF just fine (it's sort light amber in color) I think, and I've not thrown any codes since replacing the cracked air intake hose and replacing the PCV valve & hose.

Really, those two things seem to have fixed everything.

Both are EASY to do yourself, too.

Thanks for the tip but I'm already past that as a possible fix, having bought the stock unit.

 

[badgerinmichigan]

More on P0171 & P0174

I wanted to share my story for anyone else who has issues w/ lean codes P0171 & P0174.

I have a 2004 Mazda 6 that I bought used w/ about 40K miles, it now has around 54K miles. My issue started w/ just throwing one code. I knew it had to be an unmetered air leak, but I could not for the life of me find it. I checked all the vacuum hoses. I changed the air filter. I cleaned the MAFS.

Anyway, I finally got serious about tracking it down and made arrangements w/ a contact who has a scan tool to look at the HEGOs, fuel trims, MAFS, and baro pressure w/ me. My long fuel trims were just over 20% - definitely unmetered air getting in there. We cleared the codes and drove around to check for vacuum issues - but when the vehicle was accelerated, reducing vacuum, the fuel trims didn't budge. So, not a vacuum leak.

But low and behold, when he disconnected the clips to remove the airbox cover and look at the MAFS, the air intake hose split like a pair of too-tight pants! Wow! I put some duct tape on it and we checked it out again - long fuel trims now under 10% - all is well. So, we surmise that I had a weak spot starting on that hose, and the stress introduced by removing the airbox cover broke it wide open.

Duct tape is holding, 60 miles later no CEL, and I've got a new part on the way.

I am amazed at all the comments I am finding in this forum about cracking of the air intake on the V6. I'm amazed that Mazda picked a material that has such poor durability - I'll bet they sell a ton of these and never ask why it's such a good seller. Whoever makes this part for Mazda is probably pretty happy to be selling so many of them. The V6 Duratec is a Ford engine, but that air intake is unique to Mazda. I work in the automotive field, and I just cannot understand how that part passed durability testing.

I'm thankful I have access to someone who could check the PIDS and help me pinpoint the cause, I'm convinced if I went to a dealer or repair shop w/ those codes I would have left w/ a new HEGO sensor and an unresolved issue.

I wanted to share this story, for anyone else who has these lean codes and is debating what to do. Go get a roll of duct tape and then order a new air intake hose, and save yourself the trip to the repair shop.