CEL + unusual noise & laggy boost = what?

Discussion in 'Modifications & DIY how-to' started by yardhippie, Mar 10, 2009.

  1. yardhippie

    yardhippie Member

    I'll try to give as much background as possible.
    04 FXT
    3" Helix catted DP
    STi catless UP
    WBR 3" mid pipe and axleback
    AP 2.0 OTS Stage 2 93 map
    K & N Filter

    All of my mods were done by me last summer or previous.
    I cleaned my K & N about 3 weeks ago and have probably put 500+ miles on it since.

    Today I pulled in to the car wash and noticed the CEL was on. Plugged in the AP and got the P0171 (I think) AP said it was "too lean Bank 1". This is the first time I have seen this code. I have seen another one a time or two: exhaust temp outside paremeters or something to that effect. I havent seen it in months.
    Shes got about 75,000 miles on the stock components: airbox, TD04, IC and plugs (Im replacing them soon).

    So I reset the ECU and noticed it seemed a bit more sluggish than normal. I thought it was just the ECU "learning" again. Then I noticed a funny sound when I pulled through 2nd a bit later.
    I did another pull through seconded and really listened. It sounds like a very light, random ticking, or even small gravel hitting the muffler. It is really hard to describe the sound. Its not heavy and I dont feel any effect on the pull. I looked in the mirror and saw something like a cloud of light smoke. I couldnt tell a color but it was quite light not black looking. I also noticed going from part throttle to full throttle it seems to a bit laggy. The power takes longer to kick in.

    Boost is building to the mid 11 psi range according to the AP and this is where it has been since I went Stage 2. I know you can build more, but I dont drive it that hard and havent had it tuned.

    I read that a dirty MAF can cause that code and power issues. So I came home cleaned her up with some brake cleaner as suggested by WJM in another thread.

    I checked all my hoses that I can see and tug on, put her back together, reset the ECU and went for a test.

    I kept it out of boost until I could get to where I could get a good clean pull on it.
    In second gear, I slowly built up to about 3500 RPM then stood on the gas and good amount of brake to listen to what happened:
    Boost came up to the expected 11+ psi, I could hear the turbo spooling nice and smooth, exhaust sounded good too. As soon as I got off the brake and the RPMs headed up there was the sound again.

    Any thoughts or ideas?

    Thank you!
     
  2. nicad

    nicad Yes I am a troll

    compression test asap. sound of gravel/BBs in a coffee can is bad.

    can you check the AP any way and see if it's been pulling timing? is the smoke color more of a blue and not black? sounds like youre getting some knock or detonation when the engine is under load (just spooling the turbo up won't really do this)
     
  3. yardhippie

    yardhippie Member

    I have a compression test kit so I could do that.

    I dont know how to check the AP for pulling timing? does anyone else?

    What does gravel/bbs in a coffee can mean?

    Thank you.
     
  4. nsvwrx

    nsvwrx Active Member

    do you have ecu explorer or anything hooked up?
     
  5. nsvwrx

    nsvwrx Active Member

    I THINK ap v2 can do it.. not sure. use ecu explorer if you can.

    Gravel/bbs in a coffe can is the sort of sound its making.
     
  6. yardhippie

    yardhippie Member

    No I dont have ECU explorer. Where do I get it or is it with the AP software?

    The AP 2 shows two types of timing, dynamic and another type.

    Its never done this before, only started today.
     
  7. WRXCoupe

    WRXCoupe Active Member

    Trouble shooting the P0171 code is one thing, but if your getting smoke and valve train or possibly cylinder/low end noise I would hustle in to have it checked by a pro.
     
  8. Kokopelli

    Kokopelli Active Member

    A post maf pre-turbo intake leak or a bad o2 sensor is likely the problem.

    The sound you are hearing is the pistons crying for help from the the det they are experiencing.

    I would not drive the car until you sort it out. Hopefully it is not too late.



    Upon actually reading your first post I am going to go out on a limb and say the oil from the K&N fubar'd the maf
     
    Last edited: Mar 11, 2009
  9. yardhippie

    yardhippie Member

    OK, so now Im worried.
    I guess I'll be chatting with TS as soon as they open.
    This is my only ride, I cant afford for her to be down. :wtc:

    Thanks for the help.
     
  10. Kokopelli

    Kokopelli Active Member

    Swap a maf with somebody and see if it runs any better.
     
  11. integroid

    integroid Supporting Member

    I have a spare maf at my house if you to see if that is the problem. Also, this noise could be an exhaust leak. I have heard an up pipe leak sound like what he has described.

    Have you gotten the same code again? You live pretty close to me so I could take a listen if you want.
     
  12. nicad

    nicad Yes I am a troll

    uppipe leak will sound like an aircooled VW
     
  13. yardhippie

    yardhippie Member

    I called up SS this morning and he graciously agreed to work me in for an inspection.

    It seems as though I did remove the sensor from the airbox and clean it, I did not clean the MAF portion of the sensor. I only cleaned the two bits with the amber bulb in the end that is a temperature sensor (i think) and the MAF portion is up in the tube and was still quite dirty.

    SS cleaned it up, plugged up his computer and after a short drive was satisfied the cleaning had fixed the problem. :bowdown:

    yeeeeaaaah for no more detonation! Thank you to SS and Top Speed for helping me out. He claimed that I now have the cheapest repair bill on record!:keke:

    I feel like a goober missing that other part of the MAF, but hey, when it comes to tearing stuff up Id rather know its right than guess!

    So, note to anyone who searches and finds this thread: when you clean your MAF, clean up inside the tube! Two small wires not connected by an amber bulb.

    Thanks to everyone else for their suggestions and help!
     
  14. nsvwrx

    nsvwrx Active Member

    yes, dont over oil your KN filter
     

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