Idling issue - car shutting off/check engine light

[1flycdnM3]

this may be a little similar to dmo11's problem, but going to post it anyways. Int he past 2-3 weeks my cars' RPM's seem to "jump around" at really really low rpm's. On a few occassions it would go so low that the car would shut-off (2-3 times). This was intermittent for the past few weeks and check engine light would come on periodically. In the past 2 days though, every single time i turn on my car the check engine light comes on! The only thing i can think of is the exhaust (borla) since this never happened last winter. The exhaust "sputters" and "shakes" a little too.
For those of you that know me (and my car), I am pretty savvy when it comes to fixing things, but im kinda clueless right now. I have some ideas, but wondering what others think might be the problem??

my thoughts...
1. O2 sensor??
2. exhaust leak?? (not likely, it's 6 months old)
3. replace CAI filter?? (2.5 years old)
4. too much back pressure/different oil?? (not sure that makes sense)
5. need a new Hi-Flow CAT to replace the stock one??

any help/suggestions are appreciated, thanks TM3 :)

[Nick]

any chance it's the maf sensor/wiring?

[1flycdnM3]

any chance it's the maf sensor/wiring?

I haven't ruled this out either, but i haven't broken any wires and there have been no issues with it so im skeptical about this being the problem. I really just need to know the engine code(s) it is spitting out but no idea where to buy a reader?? Canadian Tire maybe??

[1flycdnM3]

ok thanks to Val i used his engine code reader and this is what came up (searched out the codes too):
P2187 - system too lean at idle bank 1
P2195 - O2 sensor signal stuck lean bank 1 sensor 1
also has a 4.2 MAP (no idea what that is or if its too high/low)

so it sounds like i may need a new O2 sensor and possibly a new MAF sensor (however nothing is broken/missing in my MAF sensor so no idea if replacing it would even help)

anyone have any ideas as to how to richen the fuel mixture (since it's
too lean")?? higher octane maybe (i use 87 currently)??

[WhiteSpeed3]

check the map sensor again

mcguyver was having the same prob as well as kokkino and on my old 3 also had this prob

first check and make sure your maf it is tight on your intake (mcguyvers was loose and caused this prob)
second give the wires on the maf sensor a quick tug cus the position of the where the maf sits on your intake is a little further out than your stock air box that it pulls on the wires (my old 3 and kokkinos had this causing this prob)

quick fix go to a scrap yard get a maf sensor from a car and extend the wires if the wires are pulled out of the socket

[Flagrum_3]

check the map sensor again

mcguyver was having the same prob as well as kokkino and on my old 3 also had this prob

first check and make sure your maf it is tight on your intake (mcguyvers was loose and caused this prob)
second give the wires on the maf sensor a quick tug cus the position of the where the maf sits on your intake is a little further out than your stock air box that it pulls on the wires (my old 3 and kokkinos had this causing this prob)

quick fix go to a scrap yard get a maf sensor from a car and extend the wires if the wires are pulled out of the socket

+1, Use the K.I.S.S method, check your connections and clean your MAF with electrical spray.


_3

[sas]

also has a 4.2 MAP (no idea what that is or if its too high/low)

MAP sensor?
If scanner is measuring this parameter in kPa or inHg , then 4.2 is too low and you must to have P0069 error too.
If in volts , at IDLE must be 1.2 V and 4.1V on a switched off engine.

[1flycdnM3]

check the map sensor again

mcguyver was having the same prob as well as kokkino and on my old 3 also had this prob

first check and make sure your maf it is tight on your intake (mcguyvers was loose and caused this prob)
second give the wires on the maf sensor a quick tug cus the position of the where the maf sits on your intake is a little further out than your stock air box that it pulls on the wires (my old 3 and kokkinos had this causing this prob)

quick fix go to a scrap yard get a maf sensor from a car and extend the wires if the wires are pulled out of the socket

ok i did this and i removed the tubing/wires from the battery box (took off the clips) so that it would be able to move more freely. I did this 2.5 years ago when i got the intake installed. Also, no wires have been pulled out and everything "seems" to be fine there. I pulled out the MAF from the intake and just had a look to make sure and it's clean as a whistle. Highly doubt this is the problem based on your suggestions, but glad i did check this over.

[1flycdnM3]

MAP sensor?
If scanner is measuring this parameter in kPa or inHg , then 4.2 is too low and you must to have P0069 error too.
If in volts , at IDLE must be 1.2 V and 4.1V on a switched off engine.

yeah the engine was off so 4.2 does sound right then...

[sas]

Apparently with MAP all is OK. MAP is not so important in your case.
MAP manage by EGR system and it's work is checked by EGR valve position sensor.

Maybe, you are right with suspicions to exhaust. With a lower exhaust pressure the sensor could to have lover temperature and lower oxygen density and voltage could to drop less 0.45V for more than 46 seconds and to cause P2195, whereas the short fuel trim could to be adjusted to not allowed lean volume and to cause P2187.
You can to check out this by scanner. Or by oscilloscop but this is more problematic and time consumpting.

[1flycdnM3]

Apparently with MAP all is OK. MAP is not so important in your case.
MAP manage by EGR system and it's work is checked by EGR valve position sensor.

Maybe, you are right with suspicions to exhaust. With a lower exhaust pressure the sensor could to have lover temperature and lower oxygen density and voltage could to drop less 0.45V for more than 46 seconds and to cause P2195, whereas the short fuel trim could to be adjusted to not allowed lean volume and to cause P2187.
You can to check out this by scanner. Or by oscilloscop but this is more problematic and time consumpting.

I did have it scanned to get these numbers, but i totally agree with everything you said and it does make sense as to why my exhaust would cause this problem. I called Mazda and can't get it in until later this week, but i still feel like im "going in blind" as to what really needs to be done to fix this. I feel like im gonna be paying way too much money for unnecessary parts/labour that i could likely do myself or something. such as new MAF sensor, O2 sensor or just different/synthetic oil or gas to richen the fuel mixture??

[sas]

Scanner can read parameters which you requesting by PID. I think, you got MAP’s data because you had this PID in request. Also you would to request “freeze frame” there is useful data too. This Depends on scanner thou.
I wrote bit wrong about exhaust. Really, low voltage is speaking about lean mixture and must to make the system to enrich the mixture. And error P2187 can to appear only as result of sensor’s sensitivity switching.
By the way you could to try the better fuel. This could to help if you have any restrictions in fuel system. You are right about “unnecessary parts”. The
technology is too complex now and one man can’t to know and to do all things.

[1flycdnM3]

so far no response from Mazda (i guess they are really busy) so i will try just putting in higher octane gas and see if that helps at all. I have half a tank left though so might have to wait until the end of the week.

thx sas

[ravin13]

Higher octane won't richen the mixture, all the higher octane does is prevent knock. You have a lean code so your not getting enough fuel, or too much air. Check for a vacuum leak, or loose intake after the MAF.

[sas]

Yes, the premium fuel theme is very slippery. But there are still present evidences of risen mileage after switching from 87 to 91 . This means less injectors duty cycle i.e. lowered fuel trim. I don’t know Canadian gases. Here I had 4-9 percents improvement with Shell RON98 against RON95. If to take in account acceleration (mapped mode) I expect 5-12 percents of reserve for fuel trim. This numbers will be less at low RPM though. And I have to say with another brand RON98 and Shell Premium I didn’t have this improvement. I forget to warn. If you, really, have a lean idle mixture or bad compression ratio the things could be worse with high octane.
I was puzzled, how scanner can convert kPa in voltage, if only it is original Mazda scanner. I see from another thread, you used Scan Gauge. Scan Guge showing pressure in PSI by default. 4.2 PSI is almost 30kPa. This is ideal IDLE pressure. I think you read it from freeze frame and now I’m puzzled how you missed RPM, ECT and another stored there data.
More obvious causes of your problem are:
leak in intake (with closed throttle even a small leak giving a big influence), leaking purge or EGR valves, clogged injectors and of course O2 sensor.
I hope it will help you to speak with MOT.
I have found good site, here many useful data about engine management if you want to know more about this. http://aa1car.com/

[1flycdnM3]

well i finally got it into Mazda today and i got an "engine upgrade" which im not quite sure what that entails, but warranty covered it anyways. I was originally told the Purge Valve Solenoid (sp?) was "gummed up" which apparently means something about closed loop vs. open loop and one was stuck (the idling one ofcourse) so im not sure if they cleaned it up or replaced it or what-not, simply because they "couldn't cover it under warranty unless the check engine light was on".... which it wasn't, because it hasn't come back on since Val reset the ecu using his Scan Gauge. However, he reassured me that IF it does come back on, to bring it back in and will be fixed under warranty. so good news and bad news i suppose. just have to see if it comes on again, but he DID recommend cleaning the MAF sensor, which is a good idea... anyone know how i should do this?? im assuming some sort of alcohol (for the car, not me)?? lol

[sas]

I'm not sure about spirit. Some plastics and varnishes don't like it.
There are special MAF cleaners. Here is being mentioned CRC product.
http://www.aa1car.com/library/maf_sensors.htm

[3GFX]

Wet filter?

[1flycdnM3]

I'm not sure about spirit. Some plastics and varnishes don't like it.
There are special MAF cleaners. Here is being mentioned CRC product.
http://www.aa1car.com/library/maf_sensors.htm

ok thanks sas, i might just go with those "towelettes" from restaurants cuz they have alcohol in them so might work just as well.

Dave, wet filter?? what do you mean by that??

[Nick]

if the filter is wet it could decrease air flow which will give an improper reading

[sas]

Do not touch it. No any towels and brushes. Only spray on it.
If no MAF cleaner then use another electronic cleaner or brake cleaner.
99% methyl or ethyl spirit may to work too, but no one tried it on mazda’s.
Better to check them before on paper and black surface they don’t
have oil and other additives. Spray it on MAF 3 times with interval 3-4 min.

[1flycdnM3]

if the filter is wet it could decrease air flow which will give an improper reading

what filter are you talking about??

[1flycdnM3]

Do not touch it. No any towels and brushes. Only spray on it.
If no MAF cleaner then use another electronic cleaner or brake cleaner.
99% methyl or ethyl spirit may to work too, but no one tried it on mazda’s.
Better to check them before on paper and black surface they don’t
have oil and other additives. Spray it on MAF 3 times with interval 3-4 min.

ok i will go check CT or other local shops for MAF cleaner as this would be a good idea even if i wasnt having problems.

[Iceman_F1]

what filter are you talking about??

I would GUESS the CAI...

[mogul_pro]

I am having a very similar issue with almost exactly the same setup you have on your car... If you figure it out please post up.. and vise versa.

[Gio81]

I had a very similar problem about 6 months ago. The only aftermarket thing i had was a Fujita CAI and everytime i did a reading it came up saying my MAF sensor was dirty. I cant remember the code now, but even after cleaning it i continued to have the problem. The idles were all out of wack and stalled on me plenty of times. I tried everything and after getting frustrated i removed the CAI and put back its original air box and canceled the error reading... now my car runs fine... minues the noise i used to love hearing :P

[1flycdnM3]

it does seem very common that it's the MAF sensor and tat's the first thing you should check. In my case, the MAF seems to be fine and no issues with it. My purge valve solenoid was all "gummed up" which i was told is another common Mazda problem and was affecting the "loop" (closed loop or open loop, cant remember) which wasn't operating properly on idle. Again. not sure if they fixed this when i went to Mazda or not since my check engine light wasn't on, but it IS covered under warranty (incase the light does come back on, i can take it in again).

[mogul_pro]

So now that you had that solenoid "un-gummed up" no problems?

[1flycdnM3]

well ok i took the car back in on Monday this week (because the engine light came back on) and got the Purge Valve Solenoid replaced under warranty. I have to admit, as much as the car "seems" to be running fine, it still has "RPM spike" but very very slightly and not enough to stall out anymore (for now anyways, seems to be much better). I have yet to clean my MAF sensor and i will do that this weekend, but this winter sure is a huge deterrent for a turbo upgrade this summer. I am thinking of holding off and buying a speed3 maybe in couple years. I think my car is a bit of a "lemon" which hardcore sucks.

c'est la vie...

things that were/will be done are as follows:
1. replace O2 sensor (maybe in a month)
2. clean MAF Sensor (this weekend)
3. replace Purge Valve Solenoid (done at Mazda this week)
4. engine upgrade (no idea what this entailed, but free from Mazda last week)

[sas]

I hope they know what they do, but IDLE spikes, sounds odd.
In order to make your weekend rest more effective:
http://www.ozmazda.com/board/index.php?act=Print&client=printer&f=68&t=2796

[S.F.W.]

4. engine upgrade (no idea what this entailed, but free from Mazda last week)

This would be a PCM flash, there may have been an update available.

[kaval]

Have you checked for any vacuum leaks? Do Mazdas have an idle air control valve?

[notoriousb]

I had those codes. I thought it was the o2 sensor as well, and i not only replaced the o2 sensor, but the maf sensor, spark plugs and purge valve solenoid. It ended up being the egr sensor. Try cleaning that.

[kaval]

Check your EGR valve!!!!

[1flycdnM3]

^^ ummmm guys?!?! problem has been SOLVED!

there were no vacuum leaks and it wasn't the EGR valve (although in other cases, this could be true, jut not in my case)

Yeah Ami, it was a PCM flash (couldn't remember what it was called) and apparently EVERY Mazda was "supposed to" get it, but as it wasn't causing any serious problems in many cars, they just did it on a "need to do it" or "requested it" basis. In my case, I can still notice it because the upgrade constantly "opens the closed loop periodically" as they told me which is keeping my car from idling too low as well. If anyone has the "shaky engine at idle" which i hear some people mention, this upgrade may help that too (don't quote me on that though)

[taojin84]

I had the exact problem as you!

it is caused by a failed purge valve. along with an outdated PCM.
a little research online shows its a common problem for mazdas.
hope that helps.

PS, dont go to the service, at vancouver here they charged me over $300 for replacing it

[taojin84]

its ur purge valve. i had the same problem

[1flycdnM3]

I had the exact problem as you!

it is caused by a failed purge valve. along with an outdated PCM.
a little research online shows its a common problem for mazdas.
hope that helps.

PS, dont go to the service, at vancouver here they charged me over $300 for replacing it

yeah they said it was a common problem at Mazda too! I think i posted on your thread about that price, they quoted me $90 or something for mine (though it was covered under MAP anyways)