Bad gasoline?

[The Pirate]

One time after I filled up I forgot to reinstall the gas cap.  The 2006 Mazda has a little vacuum pump that activates to see if the gas cap is on.  It ran and ran and burned out because I left the cap off.  There were no driveability issues though.  Just something more to check.  You might have got a bit of water in the gasoline; it happens from time to time.

Cap was definitely on, however I'll take a look at this.  Thanks.

Run this tank nearly completely empty and then refill from a reputable chain such as conoco, shell, sunoco, etc.  Doesn't have to be the costliest fuel, just something better than Jim's Convenience Store, and see if the problem goes away.  If not I'd recommend further diagnosis.  Personally I have seen a few similar issues lately due to excessive alcohol content or poor quality fuel.

Drove the car again this morning, and the CEL is still on, but the car is driving normally.  The idle is fine, it has full power, etc.  What you've said confirms my plan, so that's good to hear ().  I bought some of that HEET fuel stabilizer/water removed, I'm probably going to put that in later. 

Bad gas sucks. There's a place near home that is consistently 3-5 cents cheaper per gallon than the big guys. My brother filled up there once and had a similar experience that you're having. Even in gasoline, you get what you pay for.

Was the place you filled up at a cheap-o place or a big chain?

I generally try to stay away from the cheap-o places, this was a Sunoco that I fill up at fairly regularly (it's on the way to one of the places that where I ski).  Obviously, I'm going to try a different station for the next fill up.

Was the gas cap loose to begin with? 

It takes a few drive cycles for a CEL to go out.  Disconnecting the battery may or may not keep the light off.   Same happened with the Volvo (gas cap) and in spite of knowing that doing so was probably a waste of time, disconnected the battery.  Light came on three miles down the road.  I told the wife to drive it and the MIL went off about a week later.  Hasn't been on since and it passed inspection.

Yeah, gas cap was loose after the initial fill up.  I tightened it later that day.  After the battery reset, the CEL came back on.  As mentioned before though, the car has zero drivability issues, so I'm going to give it some time.  Hopefully it fixes itself.


Thanks for the thoughts, guys.

[The Pirate]

Okay, she was down enough for the low fuel light to come on, so I filled up (Mobil station that I usually go to).  I've only driven about 10 miles since the fillup, so it's obviously too early to see.

This morning, I ran to Advance to pick up sparks plugs (simply time to replace them, not because of the CEL).  I borrowed their code reader to see what comes up, for shits and giggles.  It was a mid-level Actron, so I'm sure it's not going to be as sophisticated as the dealer's setup as far as diagnosing beyond what code shows up.

But this is what it showed:  P0171 - System too lean (Bank 1)  

A quick search shows that this a fairly generic code in that the real problem could be a variety of different things.  I don't really have the money to be throwing parts at it, and I'm not happy with either Mazda dealership in this area.  What can I do myself to diagnose (or at least rule some things out)?  Could it still be bad gasoline, or have we moved out of that altogether?

Thanks guys.

[Laconian]

But this is what it showed:  P0171 - System too lean (Bank 1) 

Too much purple drank in the fuel.

[S204STi]

Too much purple drank in the fuel.

Also known as ethanol, in this case.

[The Pirate]

Too much purple drank in the fuel.

I just want the badness to leave my car. 

[Rupert]

Have you tried an exorcism?

[The Pirate]

Have you tried an exorcism?

No, but every time I drive down the road I wanna jerk the wheel INTO A GODDAMNED BRIDGE ABUTMENT.

Then collect the insurance money, and get a pick 'em up truck, of course.

[S204STi]

The lean code tells me that you either have a vacuum leak, misfire, or the fuel you filled up with last time had too much ethanol in it.  If it doesn't clear up with this tank I'd see if you have a vacuum leak.  Spraying carb clean at the intake gaskets and rubber bits with the engine running might show if you have one.  If the idle gets noticeably rougher when you hit a certain area, that's the source of the leak.

[The Pirate]

The lean code tells me that you either have a vacuum leak, misfire, or the fuel you filled up with last time had too much ethanol in it.  If it doesn't clear up with this tank I'd see if you have a vacuum leak.  Spraying carb clean at the intake gaskets and rubber bits with the engine running might show if you have one.  If the idle gets noticeably rougher when you hit a certain area, that's the source of the leak.

Cool.  I did some poking around on the Mazda forums (and there is a LOT of BS and fanboyism to sift through over there), and pretty much came up with the same thing regarding vacuum leaks.  They also said to check the hose to the intake manifold after the MAF for splits (not an uncommon failure on this car, I hear), and the MAF itself.  I don't think there's a misfire, but I'm replacing plugs anyway (it's time).  I do feel better now that I have some sort of concrete issue to chase, and that it's one that shouldn't be terribly expensive.

I really appreciate the help.  Quick question - okay to drive the car in the meantime?  It drives just fine, and I'm taking it easy, but I know lean conditions aren't good.  I realize the advice is worth exactly what I paid for it, and release you from any bad juju if the car blows up tomorrow.  

Thanks again.

Be awesome if it was just ethanol from the last tank, I can spend that part of my tax return on another .22 and a tent.    FWIW, this car suffered a noticeably big mileage decrease when the switch to E10 came around, and my butt dyno (however accurate that thing is) swears it lost a little pep.  Up until a few months ago, there was a station here that still had gas with no ethanol and I would go there, but they are E10 now too.

[Rupert]

I should fill up the 'Sploder with E0 ( ) and see what its mileage is. I bet it would get it up to the EPA estimate.

[3.0L V6]

I really appreciate the help.  Quick question - okay to drive the car in the meantime?  It drives just fine, and I'm taking it easy, but I know lean conditions aren't good.  I realize the advice is worth exactly what I paid for it, and release you from any bad juju if the car blows up tomorrow. 

Thanks again.

If the car's throwing a CEL, it's probably running off a preprogrammed fuel-air map from the engine computer instead of looking at data from the various engine sensors. You should be fine to drive it - but it will probably use more fuel in the meantime.

[S204STi]

Cool.  I did some poking around on the Mazda forums (and there is a LOT of BS and fanboyism to sift through over there), and pretty much came up with the same thing regarding vacuum leaks.  They also said to check the hose to the intake manifold after the MAF for splits (not an uncommon failure on this car, I hear), and the MAF itself.  I don't think there's a misfire, but I'm replacing plugs anyway (it's time).  I do feel better now that I have some sort of concrete issue to chase, and that it's one that shouldn't be terribly expensive.

I really appreciate the help.  Quick question - okay to drive the car in the meantime?  It drives just fine, and I'm taking it easy, but I know lean conditions aren't good.  I realize the advice is worth exactly what I paid for it, and release you from any bad juju if the car blows up tomorrow. 

Thanks again.

Be awesome if it was just ethanol from the last tank, I can spend that part of my tax return on another .22 and a tent.    FWIW, this car suffered a noticeably big mileage decrease when the switch to E10 came around, and my butt dyno (however accurate that thing is) swears it lost a little pep.  Up until a few months ago, there was a station here that still had gas with no ethanol and I would go there, but they are E10 now too.

Yeah, no problem.  I wouldn't worry too much about it wrecking your motor, it's not like a high-compression ratio or turbo motor, but you will most likely find that it runs better once the issue is resolved.  There is mild risk involved, sure, but the main risk believe it or not is to your catalytic converter.  A lean condition causes high exhaust temps which can damage the cat. 

[omicron]

Hang on, what? Ethanol-free fuel is hard to get?

[S204STi]

Hang on, what? Ethanol-free fuel is hard to get?

Nearly impossible in many areas.  I can't get it without 10% ethanol content without driving down to Denver and going to a place that caters to racers.

[omicron]

Well I'll be.

[Raza]

I haven't seen ethanol-free gas in three years.

[The Pirate]

Well, I think we've moved past bad gasoline.  I'm leery to call it the EGR valve, as the idle is generally nice and smooth.  But I hit 45 mph a few times last night, and push the clutch in to coast to an upcoming red light.  The revs would drop very low, to almost stalling (and the battery voltage light would flicker).  It seemed not to do it when I was applying the brakes, and is just fine when idling at a traffic light.

To me, this says vacuum leak, so I'm going to see if I can track that down tomorrow morning before work (it's bitterly cold today, and I'm already getting swamped with work for school).

Edit.

Update: Opened the hood tonight after coming home from work (engine was nice and warm, and idling quietly).  I'm pretty sure I can hear a leak somewhere between the air filter and the intake manifold.  Going to inspect more closely tomorrow, when it's light out and not so bitterly cold.  If this is indeed the culprit, I'm tempted to upgrade to fancy intake...

[omicron]

I haven't seen ethanol-free gas in three years.

I wouldn't even know if any of my local petrol stations sold E10.

[Laconian]

Does Australia have any subsidy boondoggles of its own like we do with corn? Do you have gasoline mixed with Yellow Tail?

[omicron]

Does Australia have any subsidy boondoggles of its own like we do with corn? Do you have gasoline mixed with Yellow Tail?

I'm fairly sure the sugar cane industry receives government money in some form, and ethanol fuel is probably more common up north in Queensland near the plantations themselves. A quick check on the BP and Mobil websites reveals that they don't distribute E10 outside of New South Wales, Queensland and the ACT, which is the north-east corner of the country.

Wine, on the other hand, is strictly legislated as an Omi-only fuel.

[The Pirate]

Well, half-success.  Haven't replaced the part yet, so I don't know if there are other issues, but the intake hose has a rather large split.  Mazda wants $85 for a replacement part, so I'm going to see where NAPA's prices fall.  Should be pretty easy to replace, and hopefully that's the source of the problem (seems like it would be).

The timing of it's demise was odd, and threw me for a curve ball, but looks like I might be able to get out of this for minimal money. 

[Eye of the Tiger]

Well, half-success.  Haven't replaced the part yet, so I don't know if there are other issues, but the intake hose has a rather large split.  Mazda wants $85 for a replacement part, so I'm going to see where NAPA's prices fall.  Should be pretty easy to replace, and hopefully that's the source of the problem (seems like it would be).

The timing of it's demise was odd, and threw me for a curve ball, but looks like I might be able to get out of this for minimal money. 

Try sealing it up with duct tape for now 

[The Pirate]

Try sealing it up with duct tape for now 

Yeah, going to have to do that.  NAPA online only shows an intake available for the 1.6L cars, I don't know if the 2.0L would be the same, and I'll be damned if I'm paying 80 bucks for an OEM chunk of plastic...

[giant_mtb]

Bah, just seal 'er up with duct tape and leave it that way.  No sense in buying new shit if that does the job.

Or buy some rubber tubing and some hose clamps that'll fit and make one yourself!

[Eye of the Tiger]

And unless you want one of the $300+ name-brand intakes, I would get this

http://cgi.ebay.com/ebaymotors/2002-05-PROTEGE-PROTEGE5-MP5-MP3-2-0-AIR-INTAKE-K-N-L_W0QQitemZ370327390985QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item56393b8b09#ht_3356wt_939

Because it comes with a K&N filter, and the rest is just pipes.

[The Pirate]

Nevermind, I was looking at the wrong part number.  I can get the OEM air hose for $42.  Definitely going to try sealing it up in the meantime, though.

[giant_mtb]

Is it really that bad that it warrants a replacement?  I mean...some plastic epoxy...or...?

[The Pirate]

Is it really that bad that it warrants a replacement?  I mean...some plastic epoxy...or...?

It's a pretty good size tear, and it's right on the flex part of the hose.  I'm charging my work light right now, and I'm going to run out and pull it off, and see what I can do for a patch job.  But I'm pretty neurotic about my car (and I don't want to have to deal with the tape coming off in the middle of a trip), so I'm probably going to replace it anyway.

[giant_mtb]

Gotcha.  If it's at a flex, yeah, replacing is probably best.

What do you drive, again?

[The Pirate]

Gotcha.  If it's at a flex, yeah, replacing is probably best.

What do you drive, again?

It's the car in my sig picture. 

2001 Mazda Proteg? 5-speed