Issue with my Speed 3 after DP install stuttering/hesitation

[chinyuk1]

Hi all,

I was hoping someone can give me some idea of what to try. Let's just recap what happened, I have a Mazdaspeed 3 2007 model year Prior to the problem, I had the following mod:

Cobb SF SRI
Turbo Inlet
Denso Spark Plug IVT22
Forge BPV
Boost gauge

The mod I did was install a TurboXS DP. The car ran okay on stock ECU for about 1 week and then the car start to hesitate. At one pt, it would stall the car on idle and the CEL came on. The issue became pretty severe that in low rpm say 1000-3000, it would hesitate so bad that you can't accelerate the car. Imagine making a left turn and you lost power and crawling through the intersection, scary isn't it. Most of the time, I just free rev the car to about 3K and mesh clutch to move the car.

Initially, I though it was a tuning issue and I need to find a way to reset the CEL anyways. So I got the Cobb AP and map it with the Stage 2 93 with SF intake. That didn't seemed to resolve the problem, the car ran slightly better but the problem still there. I have asked this question on other forum and they ask me to check all hoses which I did and I even replace the BPV back to stock and still the same issue. Most ppl are pointing at the sensor.

The CEL is P2097, P2177 and P2187, the latter 2 points to too lean at idle and the other have to do with A/F. Just to mention one odd observation with the Cobb AP monitoring, it does seemed that the AFR is somewhat off. More often than not it is stuck sat 29.3 which may explain why I am running too lean. It does work from time to time but not always. This is even better indication of a bad sensor. I did take it back to the DP installer and we check the connection and they don't look loose or anything.

I am running out of ideal, if it is a bad sensor, which one, the MAF looks okay since the MAF voltage seemed to indicate higher when you are sucking more air in when driving and remain low at idle. As for the 2 O2 sensor on the DP, which one is responsible for the AFR?

So stuck , any help is greatly appreciated.

[Fobio]

you may need a new fuel pump, it seems. or you might have a wonky o2 sensor...

[chinyuk1]

I am thinking maybe a bad O2 sensor. I imagine if the fuel pump is the issue the DI Pressure should show me something that it isn't reaching the peak PSI (around 1700). During hesitation, I saw the PSI is still there, just seemed to be the firing is off.

[Zoom Zoom Boy]

You have an '07 MS3. Do you know if the fuel pump TSB was ever performed?
As Fobio said, the 2 most likely causes would be the fuel pump or the 02 sensors.
However, since the CEL's you're throwing match the TSB, I'm thinking that is the most likely...

See link for TSB:

http://www.o-m-g-w-t-f.com/stuff/Mazdaspeed6/01-022-08-1919b%5B1%5D.pdf

[chinyuk1]

I wasn't aware of the TSB. Thanks for the info. My only issue is how I can take the car back which is still under warranty to have them do it with all the mods. I would imagine that could be the issue cause the DP installer said O2 sensor normally are pretty robust. And yeah, insufficient fuel delivery could be the issue as well cause the car is running too lean.

[Fobio]

I wasn't aware of the TSB. Thanks for the info. My only issue is how I can take the car back which is still under warranty to have them do it with all the mods. I would imagine that could be the issue cause the DP installer said O2 sensor normally are pretty robust. And yeah, insufficient fuel delivery could be the issue as well cause the car is running too lean.

Depending if you bought your car new or not...if you bought it new and the dealer knows you, you might be able to work with them...if not, it might be a good idea to stock out and get that fuel pump warrantied before winter hits...

[Zoom Zoom Boy]

I wasn't aware of the TSB. Thanks for the info. My only issue is how I can take the car back which is still under warranty to have them do it with all the mods. I would imagine that could be the issue cause the DP installer said O2 sensor normally are pretty robust. And yeah, insufficient fuel delivery could be the issue as well cause the car is running too lean.

Always a difficult situation... Is your dealer reasonably mod friendly?

In any case, they can only 'legally' deny you warranty coverage if they can prove, or have reasonable substantiation to prove that your mods might be causing the problem. Since there is a known TSB on the '07 fuel pumps, you have a pretty good case to show it isn't the mods, since this problem manifests in even stock 2007 MS3's.

[chinyuk1]

Yes the car is new, and I was talking to my brother about this issue when they replaced the turbo in his speed6 at Scaraboro Mazda. They were willing to warrant it giving he swap out the stock intake and the BPV. Which is maybe an hour work, he was able to get away with the DP apparently which is the bigger job.

I will try to see if the new dealer at Maple are willing to do this. I guess I don't mind putting in an hour of work so I get it done w/o issue. And I will prob start by bringing the TSB with me to argue it has nothing to do with the mod cause like you said, it fails for regular car too. If they say no, I guess I will take it to Scarboro and did what my brother did to get them to warrant the TSB.

Thanks a lot for your help. Hopefully, this is the cause of the problem. At least it made sense to me cause I got the DP install in early September when the weather was still warmer so it worked quite flawlessly at first. But the weather obviously got colder in Toronto and this problem become a problem. Not to mention, one nite after checking all the pipe connection, it was a warm nite around 13~14 degree C and the problem wasn't as bad. So defn have to get this done before the weather get too cold. I did recall the first time this problem came about, it was when the weather got colder that day.

I guess this also may explain why the AFR is okay some time and not okay other time (too lean). Wish me luck guys.

[Zoom Zoom Boy]

Yes the car is new, and I was talking to my brother about this issue when they replaced the turbo in his speed6 at Scaraboro Mazda. They were willing to warrant it giving he swap out the stock intake and the BPV. Which is maybe an hour work, he was able to get away with the DP apparently which is the bigger job.

I will try to see if the new dealer at Maple are willing to do this. I guess I don't mind putting in an hour of work so I get it done w/o issue. And I will prob start by bringing the TSB with me to argue it has nothing to do with the mod cause like you said, it fails for regular car too. If they say no, I guess I will take it to Scarboro and did what my brother did to get them to warrant the TSB.

Thanks a lot for your help. Hopefully, this is the cause of the problem. At least it made sense to me cause I got the DP install in early September when the weather was still warmer so it worked quite flawlessly at first. But the weather obviously got colder in Toronto and this problem become a problem. Not to mention, one nite after checking all the pipe connection, it was a warm nite around 13~14 degree C and the problem wasn't as bad. So defn have to get this done before the weather get too cold. I did recall the first time this problem came about, it was when the weather got colder that day.

I guess this also may explain why the AFR is okay some time and not okay other time (too lean). Wish me luck guys.

Good luck and let us know the outcome.

[chinyuk1]

Okay guys, just to let you guys know, I think I finally fixed the problem. It was the primary O2 sensor at the end of the day. The AFR is now much more normal and the STFT also isn't stuck at +25%.

I am just a tad upset how an O2 sensor can fail after just over 2 years of usage. I am keeping my finger cross this one will last for some time.... only time will tell. At least the work to do it isn't that tough, took me roughly 1 hour to do the work.....

Now my car can zoom zoom again. Thanks for all the help guys.

I did pick up the part at Toronto Mazda and luckily, I got a discount being a TM3 member.... So the 15% is really nice, basically tax free.

I know I could have try to get it done under warranty but I want have to swap full stock and I really prefer not to cause I can't do the DP myself as I don't have the jacks and it is just too much work.

[Walrus]

Doesn't changing downpipes involve swapping the O2 sensors over to the new downpipe? If so, that probably is what caused it to fail.